How can I stop blue boxes from appearing on Safari Artlist.com in my MacBook Pro?

Few weeks ago I noticed that everywhere on Artlist.com I have blue boxes surrounding whatever I'm clicking on. This is somehow related with slowing down my browsing experience on Artlist significantly and also breaking on and off toggle on the website. I will attach photos. I was 1 week in a discussion with Artlist support according the problem and it doesn't seems to be on their end. I have upgraded to latest possible version of Safari (18.5) as well as the latest on my mac (Sequoia 15.5) and the problem persists. I toggled on and off the Full Keyboard Access and also toggled off Scroll to text Fragment on Feature Flags. It's weird that I experience this only when using Safari and only on Artlist. When other browsers, Artlist is running perfectly smooth and without blue boxes. When I try private browsing on Safari I still experience the same issue. I disabled AdBlockers and there was no change... I have a message pop up on the bottom left corner that I believe it's somehow related, but i am not sure how. I will upload it as well.

[Re-Titled by Moderator]