My first question is if D2JSP has a specific place for tech related inquiries? I have a VERY specific tech question and was wondering if this website (that might actually have people doing exactly what I'm doing) might have a dedicated sub forum for such queries.

My brand new laptop keeps booting me out of my D2r games as soon as I play Path of Exile for a given amount of time (usually 5-10 minutes). The reason I do this is I enjoy hc dueling but I often have to wait large swathes of time before challengers appear, and I play PoE in the meantime. I ran into some minor issues playing JUST poe (Deadlock detected?). But I set my cache to unlimited and that's been better. I load up a duel game, proc Merc might, minimize and play some PoE and come back to my character in the Lobby.

Here are my specs of this new laptop if that helps!

Minimizing games while leaving them running causes problems in general. It's been a Windows problem since forever.

Try hooking up a 2nd display to a display out on your laptop and leave d2r running on the 2nd monitor and see if it stays open.

Otherwise we need to see your event log and reliability history.

Windows based? Here is the issue if it's Windows based, I would guess the brand new laptop will ship with version 25H2
which is heavily bloated, ie background programs, services, telemetry, etc

U will need to debloat Windows, I suggest u look at Chris Titus Tech utility : https://www.youtube.com/watch?v=yKydZFJRzMk&t=1s
does not require any installation, just running powershell.