Hi and welcome. I’m going to propose the opposite to what has been said – sorry – lol, but it’s what helped with my two.
I would try in a big enough space for them to have their own space if needed. Also lots of distractions ! (So they carry on with doing, sniffing, exploring other things (like a cardboard box!) rather than focusing on each other).
Any reason why only 10 min sessions? If the female resumes normal status after he stops humping (so therefore not too stressed), it should be OK to go for a bit longer.
If she is trying to put her head under him, then that is her attempt at being top bun, but with him humping her then that is his attempt at being top bun…
So a hierarchy has not yet been determined.
Give it time. Don’t rush. Give them time in a bigger space with lots of distractions each time.
I would try longer sessions and step in if he is nipping too aggressively or for too long.
Keep us updated, please
(photos are always oo’d and aaa’d at !
)