My question is : are there any parameters that a workstation user would have touched to no longer be able to make folds below 90° with the folded sheet metal function on edge
It is often a problem related to system options that is altered over time, and which influences certain functions,
You can do a test from Solidworks Rx (see Pj) When the session opens, do the test,
If the angle passes, you will have to reset your options from the registry and possibly try to reload one of your colleagues to find the file locations etc .... (via the parameter backup help)
I think the problem is more with the settings in the "Length of the bent sheet" tab. You must select the option on the far left (Outer Virtual Intersection) to be able to lower the angle below 90°.
The dimensions of the tab labeled "Length of the folded sheet" seem to be the likely source of the issue, in my opinion. To reduce the angle to less than 90 degrees, you will need to select the option that is the farthest to the left (External virtual junction).