I am having the exact same issue with Jana Thork Pro changing back to Jana Thork Pro Bold every time I type into a text box that already contained writing in Jana Thork Pro. It's incredibly frustrating. This is happening after having had to update AI and reinstall a bunch of fonts today due to Jana Thork Pro disappearing from all my software despite being 'installed' according to Adobe Cloud. See attached screen recording.

Adobe... The constant bugs are getting ridiculous. Each version is less usable than the one before.

Have updated in the past few days (to 29.1) and am finding fonts are reverting to previously used ones when editing text. It can be a new string of text or an existing one, but it's happening when selecting all type to amend, or even when the cursor is in the middle of two characters of another font. Really irritating!

I am having the exact same issue since updating to Illustrator v29.1. This bug does not seem to affect newly created files in v29.1, only files created using previous versions of Illustrator. When I open an Illustrator file (created before v29.1) and change a font and then edit the text, Illustrator keeps changing the font back to whatever it was the last time the file was saved before upgrading to v29.1 — every single time.

Here is a list of scenarios I have already tested:
1. This affects all files created before v29.1
2. This affects all files created before v29.1 and then saved after v29.1
3. This affects all files created before v29.1 and then saved as a new file after v29.1
4. This affects all files created before v29.1 even when the text is copy-and-pasted into a new file created after v29.1
5. Does not seem to affect new files created after v29.1

As you can imagine, this wastes an incredible amount of time —having to undo these font changes every time I need to edit some text. As suggested by @monokano, if I disable "Missing Glyph Protection" in the settings panel, the problem seems to go away. When I enable "Missing Glyph Protection," the problem comes back.

I am running an iMac (3.4 GHz Quad-Core Intel Core i5, 32 GB RAM) on macOS Ventura 13.7.1.

Recommendations?

I'm experiencing this issue too. It is introduced in 29.1 (Windows 11).
I agree on both the Reproduction Procedure and the Workaround as monokano described. Thank you, monokano!

Reproduction Procedure
1. In the Preferences menu, go to Type > Enable Missing Glyph Protection and turn it ON.
2. Create a new document and add a text object.
3. Change the font or weight, save the file, close it, and then reopen it.
4. Change the font or weight again, then edit the text.

The occurrence requirement is to save the file, close it, and then reopen it.

Add occurrence requirements:
This bug seems to occur when the character style is overridden.

Workaround
In the Preferences menu, go to Type > Enable Missing Glyph Protection and turn it OFF.

We are also experiencing this issue, on only one computer at our workplace. The affected computer is updated to Illustrator version 29.1, while our other systems (which are working fine) are still on 29.0.

It seems to only happen with certain files. In one file we have a text object using the font "Horsham-Bold" (a TTF font). On most of our computers we can edit this text easily, but on one particular computer when we try typing to add more letters to this text, the new letters appear using the font "Adelle-Heavy" (an OTF font) which is a font used elsewhere in the file. We can correct this by reselecting the new text and changing it back to Horsham-Bold, but pressing enter to create a new line reverts it back to Adelle-Heavy.

On this affected computer we can create a new file with both of these fonts and have no issue. It's only a problem in certain files. I should also point out that the file in the example I described above was created on the same computer having the described problem

A couple more users are reporting this. Using different systems: https://community.adobe.com/t5/illustrator-discussions/font-changing-while-typing-happening-on-mac-amp-pc-adobe-illustrator-29-1/m-p/14992248#M427351

I unistalled and got back to version 29.0.1 so no I can't. It was too time consuming (not to mention annoying) to work like that.

It happened also if I copy a text and edit it, it will change to Avenir as I type!! (even a part of the text) I even tried to remove all Avenir font in the file but it didn't help.

I hope you will find that bug and correct it because I won't update until it is corrected.

Tha'ts all I can do for you.. except giving you the file I was working in (pdf full editable in .ai)

Stephane, the team is interested in details.
Can you reproduce it from scratch in a brand new file? It seems like very specific steps lead to it — can you try to catch the exact order?

Sure I can do that but it’s actually not file or don’t specific - it has been happening in all files and with all font/text elements.

I’ve had to revert to using the non Beta Illustrator cos it’s impeding my work so much.

Can’t see much in this GIF, but it clearly a substitution happens...
What are these fonts’ names?

Can you package this all, along with the font used, and send over to sharewithai@adobe.com, so the team can test it? Add a link to this report in the email’s body so they can track it back here, http://illustrator.uservoice.com/forums/939477/suggestions/49031171

Same issue for me. Only just started 2 days ago. Driving me crazy.

Lian, this is something new... please record this behavior as a video or a GIF and share a test file with the text object only that behaves like this.
I personally prefer using a small LICEcap app to record GIFs, but there are plenty of recorders.
With no evidence he team won’t be able to start an investigation.

The text edit is very weird since the last major update. When editing text on the middle of a paragraph, the typeface keeps changing to a previous typeface that was present on the paragraph, instead of keeping the same typeface.

Windows 10
Illustrator Beta 29.2 10