Hi Pawel,
Thank you for reaching out to us.
As I understand it, you are using an authenticator app for generating the OTP for two-factor authentication.
If you are using google/auth/Microsoft/Lastpass authenticator, then this might be due to the time sync issue between the server and your phone.
You can follow the link mentioned below to resolve this. This should work for you.
LINK: https://faq.miniorange.com/knowledgebase/sync-mobile-app/
In case if that does not work, please let us know, we can get over a screen share call to resolve this for you (OR) you can also directly reach out to us at info@xecurify.com
Thank you
miniOrange