Yes it was reported before for the 2022 release
https://forums.autodesk.com/t5/robot-structural-analysis-forum/robot-2022-can-t-see-coefficients-of-...
You are not able to input your manual value, but limited to factors listed in the combo.
This is a candidate for quick fix. Sorry for inconvenience.
Small workaround, you can copy from Excel or define combinations in the dialog. They are defined properly until you edit the factor in the table.
Waldemar Okapa
Sr Product Owner