If this works ok in ReachView, the problem likely isn’t the Reach RS’ fault.
The problem is more likely to be located between the Bluetooth link, the Trimble device and the software used.
Why use 5 hz for non-kinematic flows btw? If anything, having more data would worsen the latency, and if you are static on the point (or close to it) then 5 hz is just overkill?
See this thread: Observation time vs sample rate for q=1 fix