No feedback why online transactions are declined

I've been a Tymebank customer since 2021. One of the reasons I have an account, is to make online purchases. Until about 8 weeks ago I didn’t experience any problems. But then a Takealot transaction was declined, even though I had no problem using my card to pay Takealot in the past. Since then all local online transactions via debit card that I tried to make were declined.

I have written to TymeBank several times, but even when I submitted screen grabs as requested, I received no feedback as to why these transactions were declined.

The amounts are relatively small, so it’s not a daily limit problem. There are more than enough funds in my account. My card works fine when presented in a shop. My profile shows Online Transactions are enabled. I have received no warnings about suspicious activities. Instant online EFT transactions via Ozow work 100%, even a recurrent international transaction went through, but for some reason, making online payments to local companies, like Takealot and BobShop, with my debit card doesn’t work anymore. It keeps on saying the transaction failed or was declined. I'd like to know why.