Be careful !!! The bug appeared somewhere after 6.7upd1 .
ESXi6.7upd1 was installed on DAS SATA 250Gb hdd as usual (nine boot partitions and remaining Free space (225.51 GB).
VMFS6 Datastore was created on remaining space - no problem at that moment -year ago. But at the moment I decided to recreate DS by some reason (VMFS6->VMFS5 really). ESXi is patched to latest state(Dec2109). Old DS was deleted, free space is shown correctly, and the attempt to create new DS:
And got funny result in web interface (any browser): 
Web programmers are changing total disk size and boot/EFI partition order. Negative sizes... Any QC procedure was taken?
Will use vmkfstools instead - I'm not so risky to create datastore in the mentioned above way...