I think you can’t boot a zip !
If i compare to Orangefox (another TWRP fork), you need to extract the .ZIP, and boot the boot.img or the revovery.img.
Then if you decide to adopt it, you can use it to install the full recovery.zip to get benefit of all features..
Right now I am trying the Git script but I get:
Could not flash the dsp_a partition on device 87xxxxxx.
It does the first partition or it seems to but then give the above error. In the past I think this issue was the order I was attaching the cable. Will keep trying.
@ieder1 I have been trying to get the update OTA, but I haven’t seen the file become available yet so it may not be available OTA.
Try refreshing multiple times in the system updater,
or
https://ota.ecloud.global/official/avicii/e-3.7.3-a16-20260507618651-official-avicii.zip
So do I point my phone to that link (the post above this,top one) and download the zip to phone then local install from System Update> Local update? Won’t hurt me to try, do I do it zip format?
Edit: I download the link and did as I said above and the update installed in no time.
@piero thanks for this 
I am now at A16 3.7.3 avicii. Now to do a test drive.
So do i ! Will have the recovery working later…
Thank you every one for feedback !
I got it yesterday. I’d recommend waiting for the next version unless you don’t need WiFi.
When you come from stock android 12 with latest vendor updates, I expect you’re going to be fine when upgrading.
WiFi is working for me. I will check the 5G in a bit.
For me 4G & 5G are fine. Just WiFi doesn’t detect any networks, even after several minutes.
Do you know if your device had stock Android 11 or 12 on the moment of flashing to /e/OS?
Neither. It was an OTA update from eOS 3.6
My wife OTA upgraded from 3.6 to 3.7.3: everything smooth so far.
I was coming from the last A14.
I upgraded from community 3.5 a14 to 3.7.3 a26 community by local update. The Wi-Fi work.
You mean from 3.6-s (A12) to 3.7.3 A16? That’s just great! 
I mean way back in time, when you purchased the phone.
Sorry, I misunderstood. I don’t remember what was on it then. I bought it with the intention of putting eOS on it in 2022. I flashed it as soon as it was delivered to me.
One thing I maybe already asked, but not able to find: is it possible to relock the bootloader?
No, unfortunately not. There is neither an agreement between Murena and OnePlus like they have with Fairphone nor does OnePlus publish the necessary documentation like Google does (at least for the moment).
After one month and a half the phone is performing well with 3.7.3, I didn’t setup the fingerprint login and I tries this evening, but it’s almost impossible: the sensor is rarely detecting my finger! Did someone experience the same behaviour? In case: was is solved and how?
Thank you, Matteo