Unable to answer "Are these opening hours still correct?" – on floor 1: RUG mööblikauplus (Furniture Store) – https://osm.org/node/7796373823 via StreetComplete 62.1:

Rio Minigolf. Open E-R 14-22, L-P 10-22. 
Address is Võru 55f (same the RUG store currently on the map.
Website: https://minigolfrio.ee/

Attached photo(s):
https://streetcomplete.app/p/321141.jpg