This happens on every site, actually zooming is not needed, just after 4-5 scroll events and browser does not react single finger events. Scrolling works fine with two fingers. I upgraded Android to the latest 12.xx before installed sfos.
With csd test tool you could verify that display is working correctly. Sounds like malfunctioning device. My guess is that there is a dead stripe somewhere on the display.
Settings → System → About Product → tap 3 times build id version number (4.4.0.68). Go to all test and run through Display and Touch screen tests.
There should be nothing special on my setup. New Xperia 10 III, used stock android about one week just to be sure that everything works before installed Sailfish_OS-Jolla-4.4.0.68-xqbt52-1.0.0.142.
I restored backups from my old XperiaX device using “ln -s defaultuser nemo” trick.
Tested with another user and browser works fine so this bug came from XperiaX backup restore. I could try to figure out what setting is causing this quite annoying problem.
Do you have saved passwords or such that you’d not like to loose from browser? If not, then you could try to reset browser profile. History and bookmarks that are visible on the browser user interface will remain still available.
Noticed that on buggy user environment font size is really tiny compared to working one. After moved whole browser config folder and restarted session browser started to work normally.