All right. So, yeah, I went back downgrading the FW, it seems they "broke" CC51, CC52 .. etc behavior in 3.10. But looking at 3.10 release info I found this:
Bank/Preset/Snapshot Up and Down messages how properly work via incoming FS1/FS7 emulation MIDI messages
and
New MIDI message (Helix Floor/Rack/LT/HX Stomp XL): CC71 engages the MODE switch
So I guess the behavior is intentional. I suspect Board/Floor/LT are in the same boat.
I wish they update the manual manual more often. Even on version F there is no mention of CC71, let alone the new 3.15 stuff CC77-81.