Online transactions get declined for no reason

I've been having this problem for more than 8 months now, and reported it several times. For some reason, whenever I use my Tymebank Debit Card for online transactions, it doesn't work. When I contact Tymebank, it says there's nothing wrong with my card. All my settings are correct on my profile - online transactions are enabled, my card isn't blocked, according to the ***** department there's no suspicious activity.

My card works in a shop, I can make payments from my online banking profile, Direct EFT works fine, but whenever I conduct online transactions with local businesses the transaction gets declined.

I do receive the OTP, I ensure that everything's typed in correctly, but in the end, the transaction doesn't go through.

I would like to know why. And don't ring me for a couple of seconds and then send an email that I wasn't available on my phone.

Please look into this, and provide me with a real solution, because the main reason I have this card is for online transactions.