Experienced the same issue yesterday in version 2021.6 (running at 48 kHz).
Mono audio track within a routing folder, panned straight up the center. No plugins on the audio track nor the routing folder.
When the track is assigned to 1-2, perfectly normal mono signal playing back.
When the track is assigned to Routing Folder -> 1-2, there's magically spread! And horribly impossible delay to play to!
Has this happened to anybody at a sample rate *besides* 48 k? If not, maybe I just run higher sample rates and keep my fingers crossed..
