Horrified that my co-founder thought I was giving him the cold treatment, because Signal told me I had sent him messages that he never received. That's it, I'm not using Signal anymore.
I see only check mark, which I suppose means "sent not received". But hours later, most messages were not showing on my co-founder's phone. A few were there, many were dropped. This might have to do with my having used `signal-desktop` (on my laptop) for those messages.
Read my blog!