Hi Michael,
Unfortunately for me, this did not solve my problem. Can we set up a call where I can share my screen? I opened a ticket (Ticket#2019021843001141 — Teams Issue) about this issue back in February and after 2 months there's still no resolution.
The ticket was escalated to Office 365 support (tier 2). I let Swapna (rep) know that this is not unique to me, so troubleshooting by reinstalling the program won't help since everyone on the team can't see files in the channel. After showing her the issue, she said her team will work on it and keep me posted, she couldn't give an eta.
The final word I got was: After testing..."There seems to be no way to restore the "link" between channel and folder. This seems to be a known bug from Microsoft."
Michael, has this bug been fixed yet?
Kindly get in touch.
Thanks!
Microsoft