I'm sure you've been through all the basics of setting up the S10 as a hotspot, but here is a guide from Vodaphone for the S10. Perhaps their perspective on the same process could assist...
https://devices.vodafone.com.au/sams...wi-fi-hotspot/
I'd also be checking out what the "Show advanced options" button could reveal as well.
(I'm puzzled why the "Wi-Fi sharing option is set to <off> in step 13 and others, but then I'm frequently puzzled by the logic used in some of these modern gadgets)