[hovatek]

tried all (in fact, they advised me to open a new thread).
I did a lot of testing doing the nvram backup with the SPFT readback function and then flash: it does not work.
I tried to do the same with nvdata: nothing.
I tried nvdata and nvram together: nothing.
I have seen, however, that after having done the root, in the Data folder there is a nvram file with an arrow with a written nvdata next to it and in the nvdata folder I find: md / NVRAM / and other subfolders up to the MP0B_001 file.
this gives me the impression that there are all the folders, but the script that starts the carousel is missing.

Lets do a quick test.
Get the scatter file and unpatched (stock) boot.img then try flashing it using Sp flash tool. Let me know if you still get the buffer error
BTW, it seems the stock roms are signed, Try SP Flash Tool V5.1532.00 @ https://forum.hovatek.com/thread-13970.html