I am now using this PowerShell code to fix my spell check. Rather than wiping out the entire directory which deletes custom backgrounds, I delete everything else in the folder.
To make it easier to run, I used the PS2EXE module to compile it to an EXE.
Get-Process -name ms-teams | Stop-Process
$User = $ENV:UserName
$TeamsFolder = "C:\Users$User\appdata\local\Packages\MSTeams_8wekyb3d8bbwe\LocalCache\Microsoft\MSTeams"
Get-ChildItem -Path $TeamsFolder -File | Remove-item -Confirm:$false -Force
Remove-Item -Path $TeamsFolder\Logs -Recurse -Confirm:$false -Force
Remove-Item -Path $TeamsFolder\tmp -Recurse -Confirm:$false -Force