I am unable to boot into windows 10 via bootcamp

Hello to anyone reading this, your help will be hugely appreciated.

I have a 2018 intel mac mini, and have had no trouble running windows via bootcamp until I played around with some settings to try and get an external Ubuntu drive to be able to connect to wifi. I'm not sure exactly what I did, but now no matter how many times I delete and re-install windows, the following happens.

1. Create partition and go through bootcamp steps - successful
2. boot into windows for the first time and go through windows setup - successful

After this, the mac restarts into mac OS. The Windows partition is visible both in finder and in the startup disk selector. If I select Windows as startup and restart, I see a black background with white loading spinner for ~10 seconds, then it boots into mac os. If I hold option at startup, I only see mac OS as an option.

diskutil list
/dev/disk0 (internal, physical):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *500.3 GB   disk0
   1:                        EFI EFI                     314.6 MB   disk0s1
   2:                 Apple_APFS Container disk1         368.0 GB   disk0s2
   3:       Microsoft Basic Data BOOTCAMP                132.0 GB   disk0s3

/dev/disk1 (synthesized):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      APFS Container Scheme -                      +368.0 GB   disk1
                                 Physical Store disk0s2
   1:                APFS Volume Macintosh HD            9.9 GB     disk1s1
   2:              APFS Snapshot com.apple.os.update-... 9.9 GB     disk1s1s1
   3:                APFS Volume Macintosh HD - Data     271.1 GB   disk1s2
   4:                APFS Volume Preboot                 2.1 GB     disk1s3
   5:                APFS Volume Recovery                1.2 GB     disk1s4
   6:                APFS Volume VM

fdisk: 1> p
Disk: /dev/disk0	geometry: 7602/255/63 [122138133 sectors]
Sector size: 4096 bytes
Offset: 0	Signature: 0xAA55
         Starting       Ending
 #: id  cyl  hd sec -  cyl  hd sec [     start -       size]
------------------------------------------------------------------------
 1: EE    0   0   2 - 1023 254  63 [         1 -   89920767] <Unknown ID>
 2: 07 1023 254  63 - 1023 254  63 [  89920768 -   32217344] HPFS/QNX/AUX
 3: 00    0   0   0 -    0   0   0 [         0 -          0] unused
*4: 07    0   0   0 -    0   0   0 [         0 -          0] HPFS/QNX/AUX

I have attempted many of the steps I have found across multiple similar help posts, but still haven't had any luck.

Any help would be hugely hugely appreciated.

Thanks,

Elliot