As per my comment here - https://orionfeedback.org/d/6523-refresh-loops-page-randomly-reloading/165 - I reverted to 0.99.136-beta when this first happened, unaware Zotero was the cause, and it solved the problem.
The refresh loop still happens with the newest beta (138). As per magicscribe's comment, the Chrome extension has never worked for me (nothing happens when you click the toolbar button).
I am trying to see if I can get away without the extension, and just use 'Add items by identifier' and 'Find full text' in Zotero instead. However this doesn't work for grey literature like news websites.
I've posted a thread on https://forums.zotero.org/discussions linking back here but it's pre-moderated so not visible yet.