I just tried DJI Assistant 1.0.8. Same problem. I ran it also as an admin, same problem.
Yes, on the PC that wasn't working I also tried downgrading to an earlier version of DJI Assistant and it didn't help, so it seems to have something to do with the particular computer. What's weird is that the new DJI Assistant
kinda works in that it recognizes that the
P4P is connected and will display current and available software versions, etc, but it will not display flight logs or perform a calibration.
If the problem has
always existed on a given machine then it could possibly be something hardware related like an incompatible USB chipset. If you
had full DJI Assistant functionality in the past but it went away after installing DJI Assistant 1.1.0 then it's possible that the DJI Assistant 1.1.0 update installed a new and incompatible USB driver. In the latter case you could try a complete uninstall, including drivers (uninstalling the drivers would probably have to be done via Device Manager, unless DJI publishes a
complete manual uninstall procedure (uninstalling from Control Panel is often not a complete uninstall.) After the complete uninstall an older version of DJI Assistant should work, if it was working before.
Last thing to do would be to just wait, if DJI gets enough complaints of problems with 1.1.0 then will probably investigate and fix the problem, but there's no knowing how long that will take. Here is the link to a report of the problem on the official DJI forum, which usually gets the attention of DJI Customer Service...
P4P Calibration "Please reboot the aircraft." help Add yourself to the list of people having a problem in that thread... the more reports, the more chance of a reaction from DJI.
But until a fix is released, worst case... try another PC.