rebooted back into bazzite without disconnecting the dock
dock now reports 4k60 but it's actually capping out at 50
went into desktop mode to check, yep 50, can not set 60
jumped back to game mode, some graphics glitching stayed on screen, tested a game to confirm 50hz cap
disconnected HDMI cable and reattached, now the display is actually running 4k60
the difference?
DP1.2 vs DP1.4
display link was stuck at DP1.2 until recon the cable, then it switched to DP1.4
Steam Deck was having the same issue a year ago
no idea what was done to fix that but it's no longer an issue