The Corner Widget doesn't appear in all corners
Where is previous versions Corner Widgets appeared in every corner, the current version doesn't show 'm in a lot of cases.
Jan, this is strange.
Please check Preferences > Selection & Anchor Display, 'Hide Corner Widget for angles greater than' value — by default it’s 177°.
What does it have for you?
Does the situation change if you tweak it?
If it does not help. can you provide the test file and the screenshot of how it looks for you?