We don't know whether you are aware of it or not, but Prime Video's customer identity verification system in Malaysia has been disrupted since September 1. The confirmation SMS that Prime Video sends to customers contains a URL link that needs to be clicked. But as you already know, MCMC has banned sending SMS with URL links as well since September 1.
We first noticed the account was inaccessible around two weeks ago while testing the Realme 13 Pro+ 5G. The application simply said please request a confirmation SMS many times but it never arrived because it was blocked by the telco company.
If the Prime Video customer helpline is contacted, they cannot help because Amazon uses SMS-only identity verification without a secondary backup system like Google, X and Disney+ Hotstar use.
Malaysia is the only country that currently blocks SMS with URLs leaving local Prime Video customers hanging untethered. They have no choice but to cancel the subscription because the service is no longer accessible.
It should be noted that this issue only occurs if you want to do app login on a new device. Devices that were logged in before September 1 can still be used without problems. For Prime Video customers we recommend that you do not log out of your account until this issue is resolved. We have contacted Prime Video Malaysia regarding this issue but are still waiting for their official response.