What to do about frequent T3 timeouts and DRW violations?

Hello - I'm trying to troubleshoot a very spotty internet connection that results in interrupted streaming, freezing during videoconferencing, etc. I'm pretty ignorant about the mechanics involved and didn't even know how to access my modem log until a couple of days ago.

I know some folks here are willing to look at people's modem error logs, so I'm putting a link to a couple of screenshots here. Any ideas? I only have one line going from the outside of the house to the modem. It's about a 40-foot run, so maybe that's on the long side. I did remove one splitter and replaced it with a simple male to male adapter, but that didn't do anything. I'm new to this house and it looks like Xfinity has been here a number of times over the years, and there are various abandoned cables and connections all around. And frankly the way the cables are routed on the outside of the house looks a little shoddy. So I'm wondering if a tech visit is in order. I was having this problem with my previous modem as well.

Appreciate any and all advice.

https://imgur.com/a/nZhEVc1