Issues like these can sometimes be fixed by unchecking all your pet filters and then rechecking them.
If that doesn’t work, then a macro using the command Bluebonnet mentioned would be a temporary solution:
Although, I don’t think that would help you place the cub in your pet battle team. Maybe, once you have the cub summoned, you can right click its target frame and click “View pet in journal”. Or maybe there’s a macro out there that’ll let you place it in your team.
I’ve seen some discussion in the Warcraft Pets discord. One member mentioned they had spoken with a GM about some of the secret pets missing from the journal and that info was passed along to the devs. Hopefully there will be a fix.
It may work if you try this in the meantime: /summonpet Snowclaw Cub
(oops just saw bluebonnet already added the summon macro)
I got the Snowclaw Cub pet today too and also have the same issues of not seeing it in my journal. I was only able to use the /summonpet macro to summon it, otherwise it is not even counting for my total pet count.