Fenix 6X Sapphire start very slowly

Lately, my Fenix 6X Sapphire start to behave slowly on menus.

I try to shut down and start again.

If i press the upper left button, the menu appears after 20–30 seconds.

I have to shut down and restart.

At the restart, the watch stay at loading maps more than 5 minutes then it started.

The watch is working slowly even now...

What issue could be?