Question....were these well rooted bulbs? Seems odd that the blooms weigh more than the pot....causing them to tip. Hmmm... I've had unrooted bulbs topple over, but not well-rooted ones. The weight of the pot and soil should be enough to keep them firmly on a shelf (I would think).
Hmmm....Good luck!!
K

OH...btw....you usually allow at least 1" around all sides of the bulb, so it would seem that a 6" pot should be large enough.
K

I'm thinking they aren't well rooted, since they are wobbly in the pot, even the one with the blossom/step removed.

Should I repot, in heavier soil?

No, the weight of the soil isn't an issue, and you want well-draining soil. You could mix a little sand into the soil (just a bit), but you need to encourage rooting. Can you give the bulbs a little tug to see if there's resistance? If there's none, chances are they aren't rooted well if they tipped over. You need to check for rotting basal plate, and if that's the case you really need to clean off the rot, dust with captan or cinnamon and let it dry. When you repot keep the water to a minimum to discourage rot.

I guess first you need to see that the root situation is. If the basal plate looks healthy, then maybe some rooting hormone would help. If your bulb needs stability, you can stake the scapes....

I've jumped around here... Sorry. Typing on phone as I think...
K

my question is do you have the bulb buried in the dirt halfway buried in the dirt, or is it sitting on top of the dirt

They are both wobbly. I planted them leaving only about an inch of bulb exposed. Was that not enough?
The potting soil was an organic soil base lightened with Perlite. Maybe too light?
I will lift the red one, since the bloom has been removed, and check the base.
The white one is looking great, and so I won't disturb it until the blossom has gone by. There is a second stem coming up, with a single bud, and what appears to be two little leaves behind it. I have staked the stems with a bamboo stake.
Thank you all, for all the feedback.

Good luck