Problem with redirect when using Theme My Login plugin

I have been using the Theme My Login plugin for many years without an issue.

This morning I tried to log in and the TML login page kept redirecting to another page which is a landing page created using Thrive Leads.

Tried clearing cache and cookies and active logins but that did not assist.

Made no difference whether I tried to go to [site url]/login/ or [site url]/wp-admin/.

This problem would have made login impossible (can’t login if can’t access login screen) were it not for the fact that I happened to have an admin page open so when I clicked on it I got a standard WordPress login screen and was able to use that to log in and I immediately switched TML off.

I have a redirect plugin installed but it does not have a redirect for the TML login page.

Has anyone else had the problem of WordPress redirecting the TML themed login page (or any attempt to log in) to another page? And if so what the issue is so I can fix it (as would like to return to a themed login but I am paranoid I will not be able to log back into my site if I do).

BTW, does anyone know how to log in to admin when no login page/screen can be accessed – is there another way to log in?

Peter