I have a site, which was created using sharepoint online, that works fine on Chrome and Firefox but not working in IE11. It works fine once I change the document mode (in developer mode) to 11 instead of 10. Not sure how to make it work without changing the document mode as this is not a solution (Can't change this setting for the computers of anyone who visits the website).
Did you add some custom code in the site in SharePoint online?
To troubleshoot the issue, check things below:
Add the site into compatibility view in IE11.
Clear IE cache.
Reset IE settings. Go to IE->internet options->advanced tab->reset.
Switch to other computer to check if the same issue will occur.
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