Only one child SA per IPSec connection

[edzilla]

If I setup a (new style) IPSec connection with multiple child SAs, only the first one works.
I've worked around that by super-netting but that's not always possible.
Is that a known limit?
Thanks!

This is what my setup looks like:

[edzilla]

So this issue was completely on my end.
I configured the IPSec VPN on the other end (Oracle OCI) as Static routing rather than Policy and that only allows one child SA.
There's not issue on Opnsense's end.