SpaceCadet shifts clash with secondary action modifiers after most recent update

I previously had both homerow modifier shift keys and SpaceCadet shifts (on a pair of the thumb keys) working but since upgrading to firmware 0.91.1+74 enabling SpaceCadet shifts disables the homerow modifiers - for shift only. The command/control/alt homerow mods all work as before.

I’ve tried exporting settings / factory reset / restoring settings but that’s not helped. Any thoughts/suggestions on what to try next would be great.

(Chrysalis 0.13.2/firmware 0.91.1+74)