I created more Flight plan from/to FIR Hungary (LHBP). Here is two example with Climbed FL
LHBP to EDDM
Route: GILE2R GILEP DCT ZOLKU DCT ARSIN/N0439F340 DCT SITNI DCT BAGSI DCT MATIG DCT AMADI Q113 NAPSA NAPS1B
and the FL STEPS LHBP/0330/ARSIN/0340
As you can see independently I flight to West and I get FL330 until ARSIN. Meanwhile FIR Hungary follow the North-EU schema as W-even, E-odd. I get it many times FL310, FL330 etc.
LHBP to LIRF (Italy special due N-even, S-odd) that is works fine.
Route: DUZL2B DUZLA DCT VEBAL DCT VBA DCT GAPRI DCT VELUG/N0424F290 Z924 MOPUV MOPU3B
and the FL STEPS LHBP/0380/VELUG/0290
You can see above that is correctly FL380 (Westbound even) until reach Italy (VELUG) where changed to FL290 (Southbound odd)
When I consulted with VATSIM FIR Hungary/ATC staff (vACCHUN) they confirmed back in the last 2-3 weeks (my guess could be possible since AIR2201) they get lot of wrongly requested Westbound odd flight levels and need a correction under clearance.
Is it possible Simbrief offer wrong Flight levels in FIR Hungary?