About ten days ago, I went to check if there might be a new firmware or an update for coin apps, and I noticed that the synchronization was taking an unusually long time, although it did not affect the coin apps updates that I made without problems. A couple of days ago I checked again and the synchronization went through in less than 15 seconds, but I think that these are common problems that have existed since LL existed.
It would be interesting to mention this to the Ledger support to see what they say about it. It might have something to do with how many connections are active at the same time to their servers. And as I said in my previous post, a restart of the app can fix it as it might connect you to a different server.
Since you mentioned firmware upgrades and I know you are using the Nano X, there should be a notification about upgrading to the newest Nano X firmware version in your app. They still haven't released it for Nano S users, and according to their support, it's going to take some more time before it's ready.
Additionally, it's a good idea to do two things before using the LL for transferring coins: Check the in-app notifications if there are any ongoing problems with some coins or networks and checking if there are any pop-ups on Ledger's
support page. It's shown on the bottom left corner. If there is an issue that they are aware of, they usually mention it there.