IE11 desktop web browser is disabled as of Feb 14th, 2023. In the later weeks IE is disabled and replaced with Edge in the later weeks. Maybe that is the reason you are seeing the drop-off in IE11 data, and it's strange that IE7 usage is increased. Are you getting any usage on Edge browser or not?
This is the IE to Edge modal:

https://learn.microsoft.com/en-us/deployedge/edge-ie-disable-ie11