man 5 ssh_config

TCPKeepAlive
Specifies whether the system should send TCP keepalive messages to the other
side. If they are sent, death of the connection or crash of one of the machines
will be properly noticed. This option only uses TCP keepalives (as opposed to
using ssh level keepalives), so takes a long time to notice when the connection
dies. As such, you probably want the ServerAliveInterval option as well. How‐
ever, this means that connections will die if the route is down temporarily, and
some people find it annoying.

So maybe echo TCPKeepAlive true >> ~/.ssh/config could prevent those dead ssh-sessions after resume. Let's give it a try.