Well now I'm very intrigued @chickpea1982 - what are the unusual themes?!
Kelley Armstrong does a good line in Urban Fantasy (also called Low Fantasy, which is fantasy set in 'this' world but hidden - HP would be low fantasy for example), with her Women of the Otherworld series.
Garth Nix's Sabriel series is YA but very good too (high fantasy - set in a mythical world).
Also really enjoy Jasper Fforde - particularly the Thursday Next series, I'm not so keen on his standalone stuff.
I really rate loads of the authors recommended on this list too - seconding Ben Aaranovitch, Naomi Novick, Trudi Canavan (particularly the original magician series), Patrick Ness (although I would recommend him more highly if he ever finished the bloody series), Pratchett, etc.
I didn't really get on with Fourth Wing. I mean, it was fine. I just didn't get the hype 🤷🏻♀️ and I've become less enamoured with Jennifer Armentrout with the more books she's released. I loved ACOTAR so I'm definitely not coming from a position of literary snobbery!
Along the booktok recommendation theme, I would recommend the Serpent With The Wings Of Night duology, IMO it's one which did live up to the hype.
Also... have you looked at any fan fiction? I'm in a bit of a Dramione phase at the moment and some of it is really very well written 😳