Getting Delay In Receiving Text Message

[#1]

Hello folk, I had a strange and annoying experience last week which I stress has nothing to do with PN!

My phone is used mostly for receiving two-part security codes and all of a sudden they stopped being received which made life difficult. 

I got friends to text me and it turned out that messages from O2 were not coming through although they were fine from everyone else. I phoned my finance organization who said they subcontracted automated calls to Amazon!

O2 expressed little interest. 

Having spent a day on the internet I gave up. Several days later I got 20 messages all at once from Interactive Investor, O2 friends, and a hospital appointment! The phone is a Samsung Galaxy A20e Android 11.

As we become more reliant, with no choice, on modern technology we have to have reliability for basic communication.

Does anyone have any suggestion as to what has happened as I really need a Plan B if it happens again?

Regards

Derren

[#2]

Moderators Note

This topic has been moved from Mobile Tech Help to Tech Help

[#3]

I have an A21s and my bank account is set up to email and text me every time there is a credit larger than a certain amount on my account.  I have always received my emails immediately but several texts have not arrived.  The same goes for texts from my mobile provider to say they've charged me my monthly fee.  Unusually there was no email last Thursday when an amount was credited my account but the text arrived.

When the bank has sent me a code in order to complete a transaction, the text has always arrived, at least so far.

No, I don't understand why this is happening either.