Bobcat s205 drive issue

[LandisCR]

I have a bobcat s205 loader. Engine runs strong all the time and functions work well sitting still but ground travel is very sluggish all the time. When loader functions are called for drive loses power. Charge pressure at full RPMs is 380 PSI standing still but drops to low 300's when I'm moving. Just did full filter and oil change. Any ideas on what to check? Thanks

 

[SkidRoe]

Is the drive belt slipping?