Firebase error - none of the tokens can be null or empty for notifications only

This error only appears for notifications such as ignition on/off. Advertising via firebase works normally and the notification arrives on the phone. What could the error be?

Log:

2024-12-09 22:46:16 WARN: Firebase error - none of the tokens can be null or empty - IllegalArgumentException (... < NotificatorFirebase:111 < Notificator:39 < NotificationManager:139 < ... < *:132 < ... < *:131 < *:176 < ProcessingHandler:184 < ...)

The firebase channel test in the notification also works correctly.

This error means that some of the users have empty notification tokens.