[Google Pixel 4 XL ROMs, Kernels, Recoveries, & Oth] GROOVYJOSHCLARK:
Just an FYI, no PD update will solve this. You have a firmware issue, stuck on 12, but you need on 11 to use PD11 (or any custom ROM other than 12 based) so there's no other way around this. You must do it the way I'm telling you with ADB or you will be on 12P for the foreseeable future without any custom ROMs. No future PD11 update will fix this for you, so you're wasting your time trying to flash a custom 11 ROM. Fix the firmware issue then you are good to go.

Just confirm you've tried using the factory image with local usb (not the web version), and it failed, if so at what step? That works without question so what happens when you try? You won't be able to run any custom ROMs until you roll back to a 10 or 11 base firmware (current 10/11 ROMs available), and 12 is a really long time away for any stable custom 12 ROM, so you'd be missing out. Your will also be stuck on 12 until preview ends and 12 becomes official. Unless you really don't care about running anything but 12, you should really give us the details so we can get you sorted out, don't give up. Nothing worth doing, is easy, so trust me, it's VERY worth the effort to do the work, the ROM is worth it.

I really want you to get through this both as a learning step and more importantly to get you on PD11. It's really awesome, and blows away stock OS (even 12P).

If you're willing to do the work, I'm willing to assist you and walk you through it with step by step directions. I'm a senior sys architect in my day job, managing a large senior engineering team for a cloud MSP with thousands of clients so I do this every day in my normal career so it's nothing out of the norm for me. It is worth it to go through the trial and error steps to figure out what happens with trying this or that and how to recover from it when it goes poorly. I'm a huge opensource guy (linux/android), so the first thing I ever do is remove bloated stock and find a decent custom ROM or build my own, when none exist. I'm saying that piece so you understand it's important to me, custom ROMs and bloat free AOSP is the ONLY way to run android. I'm willing to do my part to help you get there as well, if you're willing to do the work on your side with me. It's that important to me to help any user wishing to get onto an AOSP custom ROM but is struggling, 'll spend hours helping that user with step by steps, or writing docs, pics, whatever is needed but you have to want it too, and willing to do the work, as well as tell me exactly what's going on. As long as you tell me what's been done, and the outcome, we can get through it but you have tell me when you don't understand or get what I'm saying. I feel that may be the issue now, I feel that I may be saying things to you that you do not understand but you're not telling me, so just tell me if you don't understand (we can even do PMs if needed), I'll get you through it, I promise, all you have to do is follow step by step directions to the T and it will work.

I'm here if you want to do the work and get it going, but you will have to be willing to follow steps and send progress so I know what's been done and what you're stuck on.

If you're done, and don't really care anymore, PLEASE let me know and I'll back off, and move onto someone else who needs help. If you do mine on, just keep in mind, you will be on A12 forever until you do the steps I laid out. The method you are using now, browser (chrome) flashing tool, cannot roll back (at least not in my experience). Using ADB with the factory image will without a shadow of doubt, roll you back and land you in a cleaned running state, ready for any custom ROM that's compatible with the base firmware (10/11). If you need help with understanding this piece, NP, just tell me, and I'll walk you through it.