Here's a video showing the issue:
I'm having trouble with the previewer right now, so I actually can't say whether the problem is that it won't update the variable, or that the variable updates but then isn't accessible to the bound text...?
This is app 173781 page 24. DM me on the forums and I can give you a link that signs you into the app so you can test it yourself. (ErinHWagner)
I am going to create separate items in case they are not related, but in addition to this, I have a page whose variable updating is completely frozen on mobile. And another page whose variable updating is iffy on desktop.