Setting up and deleting Teams folders and impact to sharepoint/O

hi - I've started to set up a Team/channels in Teams but have run into a problem.
I basically am trying to resolve sync issues related to deleted items. I would like to delete the problematic ones if it is possible as don't want to be faced with error symbols forever.

I added files in Teams, and then used Sharepoint to open, after which I synced.
This resulted in me having new folders in File Explorer with the blue building icon. This was intended - we covered it in class as a way to move files back and forth between my OneDrive folders and Team folders.

However, during the set up in Teams I unintentionally set up the Team and synced files twice. This was because I didn't think it worked the first time.
I found I could delete duplicate Team, channels and files in Teams, but am left with a problem.

I can't add screenshots here but in File explorer (left hand pane) the blue building icon still shows folders I deleted with the red symbol showing sync issues.
I can't delete the folder in file explorer because I get a message saying it is in use by another program.

On the task bar, the blue cloud icon is also showing with a red sync issue. When I click it gives me the message 2 folders can't be synced.
Clicking more information gives the Error type:
"We can't reach this library because of a service issue".
Suggested resolution is to try restarting OneDrive.
(This hasn't worked).

Any help appreciated, thanks.
James