cqrlog is attempting to use the 'realtime' single QSO upload method to do bulk uploads to Clublog.
This is explicitly banned by Clublog because it causes too much traffic.

An example:

I enter a contest and make 140 QSOs. As I make each QSO it is uploaded to Clublog - this is okay.

After the contest I upload the QSOs to LotW - this causes the QSOs in cqrlog to be marked as updated.

Next time cqrlog does a Clublog upload (either because a new QSO happens or because the menu item to do a Clublog update is used) Each updated QSO is deleted and re-uploaded to Clublog using the realtime interface. After about 25 QSOs this causes Clublog to give an "Access Denied" message and lock the user out for about 1 hour.

See the Clublog Help info at:

https://clublog.freshdesk.com/support/solutions/articles/3000023706-exce...

https://clublog.freshdesk.com/support/solutions/articles/54905-how-to-up...

https://clublog.freshdesk.com/support/solutions/articles/3000110752-ip-a...

73 Colin G8TMV