This has happened to me with several hdds.
Always in case of Hitachi ARM after replacing the head,always when p-list(PSHT)did not load to RAM and I use MRT virtual translator.
I tried all possible combinations in MRT DE.
I also tried to supply power to the hdd from an external supplier to bypass the MRT card and the computer while just MRT sata cable is connected but also here in the middle of imageing when comes bad sectors suddenly the hdd power off (with bsy status).
Another thing,at the beginning of the hdd there is access to the sectors without need MRT virtual translator and here there is no problem to read bad sectors while in the same area if I use virtual translator the problem exists (I wonder how the firmware knows how to read sectors in this area if PSHT in RAM is empty).
If anyone has any idea what is going on here and how to solve it or guide how to manually load PSHT to RAM (maybe there is a bug in MRT)(just to write PSHT to it RAM adress not helpful, need something more) I would be very happy to hear.

After further research it seems it is MRT bug.

In the attached video we can see how I created the exact same problem on a healthy hitachi ARM disc with an original head.

Time 00:24 After I wrote wrong data to the wrong address in RAM the disc turns off and immediately turns on.
Time 00:53 We see now the disk will be partial sector access mode and p-list in RAM disappeared.
Time 01:25 We are writing wrong data to the wrong address in RAM in the second time and immediately the disk turned off with a bsy state,this is exactly the problem you have when you load the translator to RAM in MRT and bad sectors appear as we see in the video Time 01:50.

Conclusion:This power off with bsy state when meet bad sectors symptom is happening when some wrong data or/and written to the wrong address in RAM so it shows that MRT loading translator to RAM not in an adequate way!(maybe as part of the process should also disable smart or relocation).