Unfortunate; This morning my firefox profile didn't start up, draws the empty window, and spins the CPU. I started my workday with downgrading FF and restoring my previous profile from a backup.
Now this.
FWIF, for this particular problem, the workaround from the linked reddit post works:
Edit 3: This workaround seems to fix it:
type about:config in the URL bar
search for network.http.accept-encoding.secure
replace gzip, deflate, br, zstd with gzip, deflate, zstd
Alternatively, set network.http.dictionaries.enable to false.
