Tvheadend

Could you try a different browser

Sure, any preference for which browser? I wasn't thinking it was the browser because the Pi would still crash even after a reboot when tvheadend executed automatically without using the browser.

A quick update before bed. I tried using Firefox, got all the way through the wizard and almost everything on the desktop was unclickable and giving the same errors as before. Detected a few less services but only QVC showed up after the mapped services step.

You didn't tell us what version of Raspberry Pi OS and TVH you used, and in particular where you got them? Since the two sets of instructions you say you are following give contradictory instructions. I suggest following the pimylifeup set and record everything you do. Either capture the commands and responses if you know what you're doing, or take screenshots. Then post them all where we can see what you've done and what happens.

What is crashing? The pi or the application?

Just note you should do all your TVH configuring on a remote machine. I’ve a feeling you were doing it on your RPI4.

Personally I’d run Ubuntu server on the RPI4 and install TVH on that. That’s just a personal preference.

Maybe you should outline what you are trying to achieve here. What frontend you intend to use etc.

In fact you could choose the LibreELEC route and install TVH server and client as simple addons.

Finally if you do get a working system setup make sure you take a backup of your SD card. SD cards are notoriously prone to corruption so it will save you going through the process again.

I was using Raspbian GNU/Lixux 10 (buster) and installed tvheadend (4.2.8-34~g24a2f59e9+rpt1~buster) following the pimylife up instructions from the terminal command line.
I was also using the pi to make the changes to tvheadend (lesson learned). The Pi runs off the 480GB solid state drive and I keep a blank SD card in the Pi to prevent the "mmc1: Controller never released inhibit bit(s) error" that is common with my Argon case.

Goals are to have a PVR/DVR media server.
I like having a desktop environment for when I do coding projects with my Pi pico (next project is a wooden pinball/pachinko machine that keeps score via IR sensors)
I liked the look and feel of Kodi with the limited amount of time I've been using it but haven't tried out any other software yet.
I want something that is compatible with the HAUPPAUGE Tuner.
I haven't experimented with other Linux systems so I like Raspbian for when I need good documentation and support.
I have all of my project files backed up so not afraid of taking the nuclear option and starting over.

Some actual output showing what you do and what crashes would be very helpful.

If Hauppauge tuner support is important I’d definitely stick with a server setup on the RPI. RPI OS Lite or Ubuntu Server install TVH which you can leave running 24/7 at minimum cost serving the streams to any other device you choose.

Install Kodi on a separate device. In fact any device you own that it can be installed on. Allow those devices do all the heavy lifting when it comes to decoding the transport streams.

Forget about installing LibreELEC on the RPI. They are migrating away from DVB device support so you’ll probably have difficulty finding support for it. You can of course install LibreELEC on another device and have the RPI serving it.

Sorry for the slow response. I was out at the IMAX watching The Marvles. No spoilers, I promise.

I did spend some time doing some research and taking the original comment about LibreELEC to heart. I decided to combine that with my nuclear option and made two separate USB boot drives.
One for Raspberry Pi OS (64 bit) for when I'm in project mode and one for the LibreELEC with the Tvheadend server and client addons.
This time the TVheadend wizard worked great and picked out all of the stations I can normally get with an antenna.
I was able to watch some live TV on LibreElec but couldn't figure out how to get my Bluetooth speaker to work yet.
Some of the stations got reasonable sounding names but many did not so for now I think I have some customization to do and a new OS to learn.
I made it through RetroPie and FalconPiPlayer so I'm sure I can come up to speed on LibreELEC soon enough.