After a recent update to windows my alt-tab to and from TFC (especially to) went from instant to around 5 seconds. This was really annoying as I do this often. I found this solution and I thought I would share in case anyone else has the same problem.
In windows 10
Go to Settings > System > Focus Assist
Toggle the switch for "When I'm playing games" to off
I play in window mode, is that weird?
yes guts, ur weird :yes: :laugh:
Turn off focus assist in windows settings, will fix it right away.