Did anybody find a solution?
I'm having the same problem in 2022.
Further to this, only parts created in 2022 have this issue. If I open (using 2022) a part created in 2021 I can select the bend lines. This seems to point towards a document properties setting.
For Christian and all others who want to get hung drawn and quartered, shot at dawn and then asked to leave the country, all because they disobeyed "good" engineering practice, I looked up the following in Help: "Drawings of Sheet Metal Parts". Also contrary to good engineering practice I followed the instructions and produced the following part and drawing: