IE11 support does not end until 14/11/2025, though older versions are now unsupported. I had a similar and just added the following line (which you want just after the
<meta content="IE=EmulateIE10" http-equiv="X-UA-Compatible">
This might do it if you add right at the top of your Head Code custom code. If it doesn’t work try right clicking outside the site page in your browser and select View page source. The line really needs to be under:
— so here —
Might be worth a try, and you can always remove it. There’s also equivalent code you can add to your .htaccess file if better for you. Just let me know.