Hi,
I would very much doubt that the Forge module is affecting sheets opening as it doesn’t touch sheets in any way (It only affects the File browser to give access to the assets library). I’d say the first thing you’d need to verify is if your d&d system is up to date on The Forge. I believe what you described happened on the dnd5e 0.97 release a while back, but was fixed since then. Confirm that your systems are the same on local and cloud servers.
I’d be interested to see if I can replicate it so I can investigate if you’re able to point at the Forge module being somehow responsible.