rounding error e-mail "an error with your payment method paypal"

[rozsnyais]

Hello,

VM:3.4.2

I would greatly appreciate if anyone could help me with the following issue:
On my virtuemart store i keep getting e-mails with the following text:
"An error with your payment method paypal on your store ***. The details are logged in the file paypal.1.log.php"

Payment arrives, but stucks in pending, I have to confirm it manually, and I don't know if client see the error?!

Afaik it's a rounding error, my primary currency is HUF, and paypal doesn't support decimals for huf currency, but vm gives values to paypal via the built-in paypal payment module with decimals.
As I checked the log, the common thing with all error payments is the decimals, while sometimes when there are no decimals then payment goes perfectly.
I tried everything: I set decimals to zero in currencies, and also set rounding for prices in configuration to 0, even tried with value -1, still no luck. It seems these set only the visible decimals, but doesn't round the value itself to whole.
How could I solve this? I read an old topic for a previous VM version, but code is different now.
Thank you very much.

Best,
Sándor