In the last couple of weeks, I've started getting this error ~1/5 times when I try to open one of my own locally hosted services.

I've never used ECH, and have always explicitly restricted nginx to TLS1.2 which doesn't support it. Why am I suddenly getting this, why is it randomly erroring, then working just fine again 2min later, and how can I prevent it altogether? Is anyone else experiencing this?
I'm primarily noticing it with Ombi. I'm also mainly using Chrome Android for this. But, checking just now; DuckDuckGo loads the page just fine everytime, and Firefox is flat out refusing to load it at all.
Firefox refuses to show the cert it claims is invalid, and 'accept and continue' just re-loads this error page. Chrome will show the cert; and it's the correct, valid cert from LE.
There's 20+ services going through the same nginx proxy, all using the same wildcard cert and identical ssl configurations; but Ombi is the only one suddenly giving me this issue regularly.
The vast majority of my services are accessed via lan/vpn; I don't need or want ECH, though I'd like to keep a basic https setup at least.
Solution: replace local A/AAAA records with a CNAME record pointing to a local only domain with its own local A/AAAA records. See below comments for clarification.
What makes it a bad cable?
This is the only audio cable I've needed/wanted for a phone in around 5 years. (note, the picture is just an example of the style, not the exact brand I happened to purchase)
For years I refused to even try wireless headphones/earbuds because I was stuck on hurdles like battery life, Bluetooth reliability/range, or the possibility of losing one; but once I actually gave some a try, particularly a good quality set, I honestly couldn't be happier and have come to prefer them over wired headphones quite significantly (specifically for mobile devices). It was genuinely a mental hurdle more than anything. Once I got off my high horse, stopped hating wireless headphones mostly on principle, and realized they actually fit my needs perfectly; I've found the only place I want/need both aux and power connections is at a non-bluetooth stereo.
So now, when I want to charge while playing music at a stereo; this cable is perfect, providing power to the phone and audio to the stereo without some bulky dongle hanging off of your usb c port wearing it out. Since switching to wireless headphones, and buying one of these cables, I have had no desire for anything else.