The glide command was actually bugged in 3.0.1 — it was incorrectly being applied multiple times on instruments that played multiple samples in unison.
The bug has been fixed now in 3.1, with the unfortunate side effect that older glides will now sound too slow, proportional to the number of samples being layered. You will therefore need to compensate the glide commands when initially importing 3.0 songs into 3.1. (We’re thinking about how to handle this automatically, but it’s not in place yet)
Please see taktik’s comment on it here:
https://forum.renoise.com/t/gxx-bug-behaves-different-3-01-vs-3-1/44506