Power steering pulley stops at extremes

I have a 2000 Tacoma - manual 4x4 . It has been well maintained and generally functions near flawlessly. I have recently noticed a new issue though that I'd appreciate any inputs and assists with please....

Issue description:
- Power steering works well - no pump whine or resistance
- At either left or right extremes of wheel travel (at the bump stops) I get what I first thought was a belt squeal .. but only at those very extremes - nothing almost all of the time as I am rarely at those extremes
- Examined belts (in good condition) as well as tension (which seems good)
- Upon further examination I have discovered that its not the belt slipping/squealing at all when I reach those extremes. It actually turns out that while the PS pump pulley is turning normally throughout most of the travel, it actually momentarily stops spinning at those extremes of travel. No pump whine at this point either.

I have never noticed this before. Is this somehow normal (does not seem so)? Outside of this PS is fine and there are no noticeable issues. Any thought and assistance on how to diagnose and resolve will be greatly appreciated as I love this truck and want to take care of it!