Yes. Thats true.
Read the DF article or watch their video @ The PS5 VRR update: tested and discussed by Digital Foundry | Eurogamer.net
Most importantly, VRR on PS5 only works within a narrow window defined by the HDMI Forum’s 2.1 standard, between 48Hz and 60Hz (on a 60Hz screen) or 48Hz and 120Hz (on a 120Hz screen). Normally a feature called Low Framerate Compensation (LFC) will kick in at frame-rates below the VRR window, essentially doubling or tripling frames to ensure that VRR remains active. For example, if your game is running at 40fps, then you could double that to 80fps to remain within the 48 to 120Hz range. On PS5 though, it’s possible to drop out of the VRR window entirely, which can lead to judder and all the other symptoms that VRR seeks to alleviate.
Thankfully, developers can implement VRR patches to mimic LFC functionality, as Insomniac has done with titles like Spider-Man: Miles Morales and Ratchet and Clank: Rift Apart. Here, the game is able to detect that you’re running with VRR enabled on the system level, and expose slightly different modes that run with unlocked frame-rates and LFC, allowing you to benefit from the advantages VRR brings without the drawbacks.