There seem to be an awful lot of input module failures on 7.3. Missing keys, cursors that either don't swap displays or won't swap back, LEDs not working, etcetera.
This has been reported by a mailing list regular with a similar issue
here. There is also a PR
here which references a fix for x11-drivers/xf86-input-mouse/work/xf86-input-mouse-1.2.2/src/mouse.c. Hopefully, this will be applied to the port ASAP. edwin@ has passed the PR on to the maintainer.