... when I try to increase the datastore I get empty
Please post some screenshots, which may help to better understand the exact issue.
Are you trying to expand the datastore from Vcenter web client.
If yes then please try to connect to host ui or direct web client and attempt the same thing.
Additionally, since the ESXi host adapter did detect the new size then you can alternatively try to use Growfs to increase datastore size via command line.
see KB:VMware Knowledge Base
Hope this resolve the issue.