That's great recommendations, but I can't recreate the problem from the samples on sencha/ which of course. is a problem if I were to open a ticket with Apple.since we tried to debug it, but safari hard crashed without any possibility to (sensibly) debug, i'd suggest that you report this to apple and/or sencha (the extjs developers), since those seem to make a problem...
(you can try https://examples.sencha.com/extjs/ to check non-pve extjs samples)
i mentioned that because @depeoThat's great recommendations, but I can't recreate the problem from the samples on sencha/ which of course. is a problem if I were to open a ticket with Apple.
Same, it seem to be an issue with Ext JS. It happens with other sites using Ext JS as well.
I updated yesterday to pve-manager/7.0-9/228c9caa and all seems to work again in safari 14.1.1 (16611.2.7.1.4).Same issue with PVE 7.0-8, Safari creates popups that are obscured by other parts of the GUI and then the whole page freezes.
Safari Version Version 14.1.1 (16611.2.7.1.4)
My solution - dont use Safari with PVE, Chrome works fine as does Firefox. Not my preferred solution but it works.