Same thing here.
After updating Helix Floor from 2.71 to 2.81 some of my (user) Snapshots suddenly generates an error code: «The Helix device failed to recall snapshot data properly». Aftrer that, an issue with the switches - they does not change when I press them. Also - after some time trying several switches, snapshots etc. - Helix freezes and I have to shut down/startup to get it going.
Also had the level issue, but setting Global Settings > XLR Outputs to Line helped. - Which tells me that the 2.81 update did NOT load the old General Settings properly (from Backup).
Until they fix this, I'll have to downgrade to 2.71 and load my fresh 2.71 Backup file. Way to many of my Patches contains Snapshots that failed, and I don't want to spend several days regenerating them.
Also - saving Patches one-by-one (from 2.71) does NOT fix this problem !!
If Line6 are listening - the attached patch does NOT load properly in 2.81!!.
(Patch courtesy of Frank Perl - some modifications made by me)
Mesa Boogie JP2C.hlx