When I checked the log, it seems there is a problem when fetching the exchange rates
Here is part of the log.
2024-05-27 02:12:15.793:INFO:Synchronizing FIO account 2d392067-1459-62ec-b131-aba06c6e51b0: success (6948 ms)
2024-05-27 02:12:11.223:INFO:Received OBT list with 0 items
2024-05-27 02:12:11.096:SEVERE:IOException when sending request getVersionEx
2024-05-27 02:12:11.079:SEVERE:IOException when sending request getExchangeRates
2024-05-27 02:12:10.555:INFO:Connecting to https://wapi.mycelium.com (0)
2024-05-27 02:12:10.552:SEVERE:IOException when sending request getVersionEx
2024-05-27 02:12:10.533:INFO:Connecting to https://wapi.mycelium.com (0)
2024-05-27 02:12:10.529:SEVERE:IOException when sending request getExchangeRates
2024-05-27 02:12:10.283:INFO:Received 0 sent requests
2024-05-27 02:12:10.045:INFO:Received 0 pending requests
2024-05-27 02:12:10.015:INFO:Connecting to https://wapi.mycelium.com (0)
FIO account shows a success but look at the ping it's pretty high and for wapi.myceium.com as you can see it shows 0 ping meaning the wallet can't connect from this site and request the latest exchange rate.
Same here with the Mycelium app on my phone but sometimes it does work it slows down sometimes when I check but at first I didn't update I just tried to change my phone DNS to Cloudflare and the exchange rate hasn't updated yet and still the connection according to logs same as before 0 ping which I think this site wapi.mycelium.com is dead.
Also, tried to ping this domain but requested a timeout and tried to access it with the browser but it showed 404 error.
This might be the reason why it can't request the latest data from Mycelium they should change the source of the exchange rate to another source if they can't provide this data or if they don't want too much traffic who requesting this data they should have a 3rd party source that can provide that data without limit like a sample from coingecko this should fix the wallet app issue.