exfat partition suddenly missing when using win10

I have some unique needs that drive this configuration. Win 10 is used to access a data acquisition system on a car. I also use Open Office apps to access various setup notes and diagrams and create track notes at the same time. It takes too long to bounce back and forth between OSs to be effective at the analysis of the data.

Once the basic work is done at the track I'd rather use the machine as a Mac to do further work that does not involve the unique Windows software.

output of diskutil list:

/dev/disk0 (internal, physical):

  #:            TYPE NAME          SIZE    IDENTIFIER

  0:   GUID_partition_scheme            *2.0 TB   disk0

  1:            EFI EFI           314.6 MB  disk0s1

  2:         Apple_APFS Container disk1     199.8 GB  disk0s2

  3:    Microsoft Basic Data data          1.7 TB   disk0s3

  4:    Microsoft Basic Data BOOTCAMP        78.8 GB  disk0s4

/dev/disk1 (synthesized):

  #:            TYPE NAME          SIZE    IDENTIFIER

  0:   APFS Container Scheme -           +199.8 GB  disk1

                 Physical Store disk0s2

  1:        APFS Volume Macintosh HD      11.2 GB  disk1s1

  2:        APFS Volume Macintosh HD - Data   30.8 GB  disk1s2

  3:        APFS Volume Preboot         83.9 MB  disk1s3

  4:        APFS Volume Recovery        528.9 MB  disk1s4

  5:        APFS Volume VM   

Old mouse is a BT mouse as well (2008-ish vintage). New mouse is a new Omoton. I'll check again, but both are paired with their respective sides but won't pair with the other....

Yes, the disk shows up in windows disk management. I've only used the MacOS disk utilities to manipulate the partitions (and have done this only once, at setup, although I do want to create another MacOS partition for my photos because there I lose a lot of functionality storing photos on exFAT.

I don't believe I specified a drive letter. I do have a variety of USB disks I connect for external storage. Some exFAT, and the one I back up to is MacOS.

On the mouse side, the windows system simply will not recognize the new Omoton BT 5.0 mouse. When I try to add a new BT device it picks up other devices in the house, but not that one. On the Mac side, if I turn off the new mouse it will eventually find the old one and connect. If I try to then connect the new one, I have to disconnect the old one, and the system takes a very long time to establish the connections. I'm not going to worry about this issue anymore.

So that worked. Had to change volume=1 to volume =0, but I was able to access the exFat disk and all of its data.

However, after a re-start it reverted to the usual.

Three questions:

1) what is causing this (given that it did not occur for months several uses after I installed windows/bootcamp)?

2) will I need to write a batch file or script and put it in the startup folder to prevent having to do this every time in the future?

3) is a better solution to this problem purchasing a product that allows the mac/pc read/write processes between their file systems and just go back to a mac partition vs exFat? That would certainly solve a couple of other issues with Mac apps that lose functionality without their file system (Photos for instance). If so, do you have a recommendation for a product?

Well, I really didn't want to do the VM thing, but if I ran it in a VM, would I even need to use the exFAT partition? Or do you still need separate file system formats in a VM?

I can see now that a solution like paragon for the Mac is not the way to go. My problem is not Mac read/write to NFTS.

There is a product called HFS+ for windows that allows windows read/write capability to HFS and has an automount feature. Would this be a good solution?

If not, and I have to run a batch file at startup, could yo suggest the proper syntax/. (I'm not much of a programmer obviously)

Thank you for all your help. this has been a fascinating lesson.

I wasn't very clear before - After some more research, I've come up with this concept. I was mistakenly referring to HFS when I meant APFS:

1) re-format the "data" drive (currently the exFAT item we've been discussing) to APFS. I need to migrate my data and move my home file, because right now the disk utility won't let me re-size that partition.

2) install Paragon APFS for Windows on the Bootcamp side. Already did this using their trial version and it can see the "Macintosh HD" volume and recognizes it as APFS and since its encrypted, won't mount it (which I suppose is a good thing).

Supposedly, if my data drive were APFS it would give me the option to mount it automatically in read/write mode.

It seems to me this is the simplest way out of this whole mess, preserves APFS functionality, and doesn't cost a lot.

Thoughts?

Correct - the problem is that it is missing in windows explorer.