Broken example for Nha Trang, Vietnam:
https://graphhopper.com/api/1/geocode/?q=Surat%20Thani%20Province%2CThailand&point=9.5013944%2C99.9956193&reverse=true&format=json&provider=nominatim
Broken example for Surat Thani Province, Thailand:
https://graphhopper.com/api/1/geocode/?q=Nha%20Trang%2CKhanh%20Hoa%20province%2048058%2CVietnam&point=12.2431693%2C109.1898675&reverse=true&format=json&provider=nominatim
Working example for Amsterdam, Netherlands:
https://graphhopper.com/api/1/geocode/?q=Amsterdam%2CNorth%20Holland%2CThe%20Netherlands&point=52.3727598%2C4.8936041&reverse=true&format=json&provider=nominatim
I think this is very serious problem, in any case it hinders us when working with the service.
P.S. Reproduces only with nominatim provider.