Blank page when testing

New install. Wondering if 4.9.6 broke postie, or if another issue. Just installed for first time after updating wordpress. No errors in logs. But if I click on Process Email, Debug, or Test Config, the page goes white, and no posts are pulled.

There were errors initially that showed up in logs, and the plugin was clearly not working. But now there are no issues, no errors. Just white page and nothing else happens.

Any suggestions? Thank you!