On a new wheel hub assembly, is it normal for the inner race of the outer bearing to pop out with very little effort? Is it also normal for the same race to be pressed back in?

Scenario for anyone willing to share knowledge with regard to wheel bearing replacement...

I found alot of play on the front driver side wheel consistent with wheel bearing wear. Never performed wheel bearing replacement but it seemed easy enough based on advice from a friend.

When I took off the old hub assembly, the inner race for the outer bearing fell right out. I assumed that this was bad, as it appeared that it needs to be pressed in, which I couldn't do with the tools I have.

So I buy some aftermarket replacements (Timken) and other than being new, they have the same issue with the inner race. I bought two, and both popped out when placing the hub assembly on the spindle, and they will not go back in without a press. I was very gentle, especially the second time. If this is normal, how the heck do the pros get these things on?

Thanks so much for any help with this, even if you direct me to a thread where this has already been covered.