Unknown axis in rlig

Hello, I have a very odd bug. I get this error upon export as VF:

Unknown axis “RYTL”
Found in: feature 'rlig', line 8. Did you mean “RYTU”? Found in: feature 'rlig', line 8.

I have two custom axes, RYTL and RYTU. The odd thing: When add a space character add the end of the name for RYTL ("Lowercase Rhythm "), the VF export works. If I remove the space at the end, the export doesn’t work.

I sent the file to support at.