So I have a very strange scenario that's happened a few times now.
First, my setup.
I've got a PLEX server installed on a Windows 10 PC in another room. My PLEX Media Player is on my HTPC in the living room. The server PC is connected to a switch, which daisy chains to a MOCA 2.0 (Actiontec) bridge to get downstairs, where it plugs into an ASUS RT-AC87U configured as just an access point (no routing/NAT/etc). I use the RT-AC87U's built-in switch to connect my Roku, TV, and HTPC, and also it's the access point for my home WiFi.
I've used this setup for years, except for the PLEX Media Player part - that's new. I was previously a die-hard Kodi user, but I'm trying to swap to PLEX for its parental controls features.
Anyways, my problem. PMP starts up just fine and I can browse my library and play whatever I want. I run into problems though if I try to jump around 'too much' or stop/start playback 'too quickly'. I'm putting those in quotes because the problem only seems to happen if I navigate within a media file a whole bunch in a short-ish period of time, when jumping around within a media file only once or twice seems fine.
Anyways, so if I start playing something with PMP and then stop/start playback too quickly or move around (fast forward or rewind) too much, the RT-AC87U literally freezes up and stops pinging. I've got to power cycle the damn thing to get my network back.
This does not happen at all with Kodi playback, or MPC-HC playback, of the same files. It's exclusive to PMP, and I'm at a complete loss as to why it would be happening. From the perspective of the HTPC, the RT-AC87U is nothing more than an ethernet switch, or at least it should be, but it absolutely locks up.