Sorry, I just recognized that you already said that the webapp behaves identical - my bad.
Anyways, let’s dive into the database now to see what’s going on here.
Do you recall the name of the playbook?
If so, you could try to run the following query in your database, which will list all the available playbooks (here’s an example from one of my systems):
mattermost=# select id,title,deleteat from ir_playbook;
id | title | deleteat
----------------------------+-------------------------------------+---------------
crypticid1 | Veronika | 0
crypticid2 | product build playbook | 0
crypticid3 | Incident Collaboration Playbook | 1616404135729
In this example, the last playbook has been deleted. Most likely also not the reason for your problem, because others can still see it.
You could also additionally query for the teamid attribute in this table and verify that the playbook and you are actually in the same team, which could also be the reason why your colleagues are seeing it and you don’t.