Don’t worry, Marco.
I still suspect the problem lies in the behaviour I described below, and it’s a bummer it causes us loose time. From this point of view this bug report can save someone’s sanity and raise a general awareness this problem occurs.
So thank you for reporting this, and don’t hesitate to report.
Surely come back if you ever catch it again!

This is odd..... I can't replicate it myself anymore either :(

Well... sorry to have wasted your time I guess.
No idea what happened there.

Thank you

And hi again.
Perhaps I am doing something wrong, but I can’t replicate it.
Can you? If yes — can you try to record a video of exact steps you take exactly?

Hi Egor, yes positive about that because the text in InDesign was set in COLUMNS, and all to flow across 4 pages. SO by COMMAND+A all of that copy and then Command+C and then going to illustrator, opening up 1 text column, and OPtio+Shift+drag to duplicate that 1 column next to it, and then COmmand+P pasting all the copy in the first column, and then clicking the icon in the bottom corner of that first column and then placing it on the new and duplicated column to get the text flow across the two columns (I don't think there is a way in Illustrator to have a text box with multiple columns so the work around I did is the only way?), in any case after doing this procedure described, the text on the right column appears stretched horizontally. That's why I mentioned a bug. Looking forward to hear. Attached screengrab showing the text in InDesign in 1 single text box with columns.

As mentioned, the issue does not occur if the copy is pasted first in text box and rich text format eliminated, made plain text, and then copied in Illustrator, there is no deformation of any kind.

This requires more info, please.
Can you share test files and exact steps to reproduce this?
Do you copy the text or text objects?
Are you sure the text you copy from InDesign is unscaled in the first place?

Hi, thank you. I actually think it's a bug because I realised that the only reason why this is happening is because I have copy pasted text from InDesign 2023 to Illustrator 2023.
If instead I copy the text from InDesign 2023 to Text edit, then make the text plain text with no rich formatting, and THEN copy paste it in Illustrator, then the issue does not arise anymore. So I think there is a slight bug there between copying between applications....?

The thing is — if you scale ONLY the area text with the bounding box, the frame gets scaled fine.

If you select an area type object AND something else — it is treated differently.

If you want to scale the frame only, but with something else — you have to select this something and the FRAME.
In the GIF I do this with the Group Selection tool and a VERY precise click.

Does it explain the issue?

Marco, for some reason your text has different horizontal scale applied to it, a different one for every other portion of the text.
Once you reset is in the Character panel, it works just fine (just Select All and type 100% in the Horizontal Scale field).

The other question — how did it happen in the first place?
Can you describe in details how does this design happened to be done?
Was it a template you used? Where did you get the text? Were you scaling some of the columns? — especially this. If yes, what tools did you use to do it? What was selected exactly when you stretched the columns?