Problem in selecting TTFStem

I’m starting to TT hint a typeface. I have entered compatible TTFStems with the custom parameter on both masters.
When I add a stem Hint to a letter, no particular stem on the list gets assigned to it, so the info shows “auto”.
When I try to change it to the first stem on the TTFStems list, it just stays as auto. Other stems on list work, only the first doesn’t.

If I open on older hinted typeface, the stems hints that were assigned the first stem in the stems list now show as “auto” too

I fixed it.