Murcielago Have you perhaps changed some settings in the default SMS app? Maybe long press Messaging icon>App info> Storage & cache>clear storage + clear cache helps?
I have tried this it does not seem to help.
Murcielago If you have installed another SMS app in addition to the default messaging app, you could also (temporarily) uninstall it to rule it out as a source of error.
QKSMS was actually much more reliable in terms of receiving SMS in other profiles but I switched back to the default as it does not seem that app is actively developed. This issue also happened regularly with the simple mobile tools sms app, and I am assuming it probably does with the Fossify version of that app as well.
Murcielago Also make sure that cross-profile notifications are activated in all profiles in which the notifications should arrive: settings>system>multiple users>send notifications to current user.
This was the first thing i checked but I appreciate you mentioning it.