Domain mapping plugin locks me out of website

I have installed the plugin Domain Mapping and activated and followed the onscreen installation instructions. However, when I try to log back into my site, I receive the below address, which keeps me in a loop and prevents me from logging-in.

https://sitename.eu/wp-login.php?redirect_to=https%3A%2F%2Fsitename.eu%2Fwp-admin%2F&reauth=1

After disabling this plugin, I can then, log back-in. However, after I re-enable this plugin, it again, locks me out, with the same above address and stays in the loop.
How to fix this conflict...help much needed. Thank you all in advance
Peter