Those of use who tried to help are also boneheads because no one asked which version you had.
Actually, until today I didn't realize there was a CS version of MixBox! I see there's also an SE version. Didn't know about that, either. So its another learning experience!
Glad you figured it out and solved the problem.
EDIT: Just did some research. I also got CS added to my account a couple of months ago when MixBox 1.5.0 came out. Evidently I knew I received CS, but since I already had MixBox, I totally forgot about it was added (July 2022). Just looked at the MixBox webpage. For the benefit of others who might have the "missing presets issue," this is what's included in the "What's New in v. 1.5.0" list of changes:
SE edition available for purchase, with upgrade path to Full
CS version available with 8 starter modules and over 30 new presets for free