auto emoji/rapid request burst and flickering

Steps to reproduce the problem

Hover over an emoji displayed as :something:

Expected behaviour

Either it can display the emoji or it gives up quickly

Actual behaviour

a very rapid flickering of the :whatever: as it disappears and reappears generating a network burst

Detailed description

frequently (but not always) when hovering over an emoji displayed as :something: I see a very rapid flickering as the line reformats to condense the emoji text and then it reappears. This is accompanied by a rapid network burst of it repeatedly trying to fetch the image hundreds of times. It's not clear to me if it's the 'auto' mode on the emoji or not, because if I go to the settings page and try changing it then it stops happening, but even if I don't change it and just reload after having gone to the settings page it seems to have stopped for this session

Mastodon instance

mastodon.org.uk

Mastodon version

v4.7.2

Browser name and version

Firefox 155.0

Operating system

Linux/Fedora/x86-64

Technical details

See attached screen shot of it repeatedly trying to fetch the image