SInce using FF 55.03 we have noticed on every PC that the dropdown menu that selects groups is very slow to respond. This has never been an issue up until the last update. In Logmein we have multiple groups (about 100) and they take about 2 seconds to display in FF, and another 2 seconds to select, which makes them unusable. We have now loaded FF ESR 52.3 and it works fine in this with instant response, so there is some problem introduced in the latest version of FF. Logmein support aren't aware of any issues. I attach a heavily redacted screenshot that shows the menu where you pull down the group selection