Google and Cloudflare sometimes show old IPv4 address

I’m having weird behavior with Google and Cloudflare DNS responses. I have 4 zones and I update them via Powershell script when I get new IPs. It uses https:[HOST]&token=[TOKEN]&ipv4=[IP4]&ipv6=[IP6]&ipv6prefix=[PREFIX]

Works well. But not always. Example:

I updated all zones at [2021-04-16 16:49:09 CET]. No errors (‘Addresses updated’).

But so far nslookup sometimes returns the wrong/old IPv4 address for the last updated zone and sometimes the correct/new one. All other zones and all IPv6 addresses are fine.

I know you are saying that not all of the Google/Cloudflare DNS servers have been updated and that it is not your responsibility. But why only the last updated one? And why only IPv4?

If I update the address in the web interface now [2021-04-17 06:18 CET] (I first have to enter a different wrong IP and then the correct/current IP, otherwise it will not be updated), then everything is okay.

This happens several times before. Should I add a wait between the 4 zone updates? The process doesn’t take a second in the script.

Do you have any advice? Thanks!