At least so far, I can report that the controller button issue appears to be resolved on my Xbox One S.
Hat-tip to Teejay6455 for starting this thread, and a thank you to all who reported in. Carry on!
Serious Bug FH4: Controller Buttons on XB1X not working after resume from Instant-On or longer pause
For the 12 month period that this thread was inactive, I can sadly confirm that the issue has somehow appeared on the PC version of FH4. If there is any fix from any of you guys that I could use, it would be greatly appreciated to send it in.