After updating to One UI 8.0 Modes and Routines (Ver no. 4.9.04.13) seems to be extremely buggy. Modes and routines doesn't automatically load after your phone boots and only starts if I create a new routine in Modes and routines. Also apparently it is getting killed in the background from time to time being totally unresponsive.
Also only one notification triggered routine will run at a time so if you have another routine triggered by a different notification from a different app it will terminate the first routines which has no relation to second routine except both are triggered by different notifications. I am very frustrated by the update due to broken Modes and Routines because I was using these routines for years now without experiencing and major issue like this time.