This error message is a bit misleading as its not devices that are being counted, it’s the number of unique connections to brave that is being counted, for example having 1 device with 3 profiles all linked to uphold will count as 3 devices out of possible 4.
If for some reason your device breaks the connection to uphold in some way, due to reinstall of OS or Brave or resetting the whole brave account with the reset wallet button and you re-connect uphold, this will count as a new connection and you will lose 1 uphold connection and this adds up over time… a lot of people are in this same boat, as am I, where I have BAT but can’t transfer it…
hopefully something changes in the future but this limit is not very good for Brave