Android 10 and 11: Get new random MAC for same SSID without factory reset Here https://source.android.com/devices/tech/connect/wifi-mac-randomization is the MAC Randomization described and stated

Note: Randomized MAC addresses are generated per SSID and are
persistent.

I can confirm, deleting the SSID, rebooting and connecting again there is the same random MAC as before. However if you reset the device to factory defaults and connecting to the same SSID, the device connects with another random MAC address. So how can you trigger this behaviour without doing a factory reset?
The key related to MAC randomization is only generated for the first time.
And the MAC address is calculated by calling hmac_sha256 over the ssid with the generated key.
This key is stored in the /data/... on the device, and as far as i know, Android does not provide any API to remove it.
But when you perform a factory reset, all the data located under /data/... is wiped out,
that's why the MAC address changes after that.
Therefore, if you can manage to remove the key, you can trigger this behavior, which is not easy, in my opinion.