I can still change pages with the keyboard, but not the mouse any more.
I have one Desktop 5x4.
I am using my own cobbled together configuration, not the default.
I saw an issue that I think was a about this on github, but it seemed to say that it was resolved.
Well, this is just brutal. 
It’s bad enough that I have to use Vimium C in Firefox to avoid the mouse. Forced to use Vim editor which traps me to a keyboard , stuck in tmux.
Simply horrible.
I guess I’ll have to build that little platform to raise my chair up a bit to match my desk.
Boy, you would think that I could procrastinate forever, but no.
Seriously though, if you have to use a mouse, they do make a few left handed ones. I use a mouse on both sides to relax each hand as needed. I use the keyboard as much as possible.
Thanks for the hard work updating FVWM.
I think the fix was after 1.0.9, have you updated to the current commit in the main branch to test if the fix works for you?
I will investigate. OpenBSD has some very powerful security measures and importing an update to a new version like this is probably beyond my capabilities. But both branches of fvwm have a maintainer, so I will see what is available right now at the bleeding edge of -current.
Right now they are trying to add a powerful new security measure, so something new might be on hold. I will go check the mailing lists. Fingers crossed. 
From an OpenBSD developer: No, an update isn’t needed as the latest changes on Github are not relevant to this problem.
So it is most likely a problem with my configuration. It’s pretty simple right now and I am wanting to make quite a few changes anyway. If I stumble on a fix, I will post it.