Hi @Pia just letting you know that we’ve located and patched the source of this issue - so it turns out its related to some incorrect HTML tags in your community header includes file which was manifesting itself in this weird issue when we made a change to the way third party includes are processed.
We initially thought it was all communities with a customer SSI includes file affected - but it actually only seems relevant for 2 customers.
I’ll contact you (and the other customer) via the support desk with the specific changes that will need to be made to your Includes file - just to ensure the HTML is valid and will be compatible to any changes we make to the SSI includes going forwards.