Activation fails all of a sudden in distributed setup

Hi Andreas
thank you for your really fast resonses, but infoirtunately the problem is not solved.
Now our biggest slave site which holds 11k hosts and ~120k services is also affected on every 2nd to 3rd activation. But here i can solve the problem with an “omd restart”.
The master site and and the second biggest slave site are not affected.
I had a look in the directory you mentioned:
The slave sites look like this:

drwxrwxr-x 2 INFMON01_3 INFMON01_3 4096 Jul 30 07:26 auth/
-rw-rw---- 1 INFMON01_3 INFMON01_3 35 Jan 27 2020 automation_secret.mk
-rw-rw---- 1 INFMON01_3 INFMON01_3 8 Jan 27 2020 last_bake.mk
drwxrwxr-x 2 INFMON01_3 INFMON01_3 4096 Jul 30 05:24 log/
drwxrwx— 2 INFMON01_3 INFMON01_3 4096 Jul 22 05:44 php-api/
drwxrwxr-x 2 INFMON01_3 INFMON01_3 4096 Jan 27 2020 snapshots/
The master site looks similar but has some additional files in it:
-rw-rw---- 1 INFMON01 INFMON01 0 Jul 30 09:53 replication_changes_INFMON01.mk
-rw-rw---- 1 INFMON01 INFMON01 632 Jul 30 09:51 replication_changes_INFMON01_1.mk
-rw-rw---- 1 INFMON01 INFMON01 632 Jul 30 09:51 replication_changes_INFMON01_2.mk
-rw-rw---- 1 INFMON01 INFMON01 2978 Jul 30 09:51 replication_changes_INFMON01_3.mk
-rw-rw---- 1 INFMON01 INFMON01 129 Jul 30 09:53 replication_status_INFMON01.mk
-rw-rw---- 1 INFMON01 INFMON01 193 Jul 30 09:58 replication_status_INFMON01_1.mk
-rw-rw---- 1 INFMON01 INFMON01 227 Jul 30 10:01 replication_status_INFMON01_2.mk
-rw-rw---- 1 INFMON01 INFMON01 227 Jul 30 10:01 replication_status_INFMON01_3.mk

I just noticed that the “Discard changes” action also reset the notifications.
I just got them back from a backup.

BR