Male heterozygotes on X chromosome

Hi all,

I am working with the WES data set of the UKB in Hail, on a gene located on the X chromosome.

Before quality control, I have 2.5k sites all in a non-pseudoautosomal region (checked with

Calls from deepvariant are diploid:

{2: 335236742, None: 4499900}

But I still get quite a few heterozygotes:
{False: 335138969, True: 97773, None: 4499900}

{False: 335124731, True: 112011, None: 4499900}

What might explain these het calls (which should not happen)? Would it be best to remove these GT calls?

Thanks in advance,