Commune of Akom II is missing. No trace if it ever existed. Wikipedia-FR, Wikidata.
Commune of Mbonge is admin_level=9, instead of 8. Is it correct? It is the only boundary at admin_level=9 in Cameroon. According to Wikipedia, it is a commune like any other, so why level 9?. Wikipedia-FR, Wikidata, OSM.
Commune of Kiiki is missing. No trace if it ever existed. Wikipedia-FR, Wikidata.
You should contact the (local) African community through the OSM Community Index if you haven't yet (click on a location to see contact channels for a region on the right).
I've been analizing CM's OpenStreetMap boundaries. The issues are the following:
Screenshots
Items 1 and 2:
Item 3:
Item 4 and 5: