A VMFS datastore spans 32 extents.
Extending the datastore by adding an a further extent fails.
VMware vSphere 7.0.x
VMware vSphere 8.0.x
32 is the maximum number of extents over which a VMFS datastore can be spanned.
This is a hard limit.
Create a new replacement VMFS datastore of the required size, spanned across no more than 32 extents.
Creating the datastore across a smaller number of larger extents would allow for future expansion of the datastore by adding an extent.