FPS drops to 6-10 FPS caused by vehicle pathfinding warning spam

Build: 613, v0.8.7 (Update 4)
System: Ryzen 7 7700 · 32 GB RAM · RX 9070 XT · latest AMD driver · 1440p @ 240 Hz
Mods: cheat++, gameplay++, storage++, Trains DLC — issue persists with mods/cheats disabled

Symptom
FPS periodically drops to 6–10 for extended periods, then recovers to 60+ on its own. Reproducible across sessions. Not GPU-related — toggling Hyper RX and disabling mods changes nothing.

What the log shows
Session log is 310 MB / 3.35M lines. From ~14:52 the warning rate jumps from a few/min to 5,000–6,800/min (~100+/sec) for over an hour, then tapers off. FPS drops line up exactly with these windows; recovery matches the spam subsiding. Nearly all entries are the same warning, each written with a full stack trace:

~Sim: Vehicle 'Truck #…: No job, cargo: --' has no jobs but is navigating. Some job did not cancel navigation?

Plus: seems to be idle for more than 60 seconds. Canceling all its jobs. and Too many PF tasks per tick.

Please post a save

100/second for something that only triggers once every 60 seconds implies you have at least 300 vehicles struggling, even at 20x speed. That sounds strange.

Latest Savegame from right now.
After i build the 3th Bridge on this Map the FPS Drops are gone.