freezes with attachments

I’ve generally been pleased with this app. I like being able to have a separate window for my work email. However, recently it has been freezing when I try to attach something. Wonder if I need to upgrade from the lite version? Also, in my ideal world, this would be available as an app across devices, not just on a macbook. But, I’m thankful to have what it is for free.

iCloud should be free about Kiwi for Gmail Lite, v1.8.97