Hi @Knight, Christopher ,
What you mentioned is a known issue that the Edge team is working on and has been fixed in Microsoft Edge Canary (version 102.0.1217.0+), so you can wait patiently for a new version update to fix this issue. You can also follow up on this case to see if this issue is resolved.
Because it may still take a while for the fix to be updated to the Edge stable version, so as an alternative, you can configure the IE mode site list via Group Policy, which won't stop working due to the exit of Edge. For how to configure IE mode group policy, please refer to this document, which contains detailed step description: Configure IE mode policies.
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