Hi, on Newsletter/Settings/General Advanced tab, set the action links to the standard format. That format can be blocked by caches, CDN, and so on. I suggest unlocking the wp-admin/admin-ajax.php file because it is designed even for anonymous calls.
If you want the link to be untracked, you can disable the tracking on Newsletter/Settings/Tracking, which applies to the newly created newsletters OR you can disbale it separately on each newsletter.
Then the tracking is off, no stats are collected but the links are not changed.
I didn’t change anything, in the August newsletter it was fine, after your plugin update it changed. Now I changed this setting to the Standard and the links works correctly. Thank you.