I may have found the issue with the Bluetooth time/date sync! There's a GMT timezone offset I haven't made in the app Scope Friend. It's under the settings menu/GMT Timezone offset. I guess I didn't set it because right above that setting there's a setting for DST, however I just reread the GMT Timezone Offset setting and it says " . . . This value is independent of the current DST setting!" I updated it, so we'll see.
Seems like that will solve my time/location Bluetooth sync operation. I'm going to polar align, then select use last alignment. After that I'll update the time/location via bluetooth and then try a go to. I bet that gets me in the ballpark.
If you are moving the mount between imaging sessions, I'd recommend using Quick Align instead of Last Alignment, so that you start from a consistent, neutral mapping of the sky. If nothing else, it's one less variable that could be a problem at some random time.
I'm also assuming by "Celestron Nexstar" you are NOT talking about the SE mounts (Alt / Az), but about the GEM-types. So, an AVX or similar. I have an AVX.
I'm using a different toolset than you at the mount, but this is my "quickest path to beer". Do a good job at polar alignment - take your time there to be precise - then turn on the mount. The mount should remember both the location from last time, and know what time it is. If not, you probably haven't enabled the internal battery. It's in the Utility menu.
Using the hand controller, slew to a bright star near your intended target, and get the camera in focus. Since the mount will likely miss the star, get it centered in the camera's field of view. With the hand controller, add that star in as an alignment star. This gets the internal alignment pretty close.
I then look up the target in my mount-control software (CCDciel in my case), and use it to slew to the target. What it does is command the mount to move, then takes a verification image. That gets plate solved and sync'd to the mount. It's going to be off a bit, so a second slew is automatically done, imaged, and solved. That is almost always dead on target. Fire up the autoguider, calibrate if you have to, and you're off to imaging!