Zip hydrotap low flow

Hi all,
Just picked up a zip hydrotap from an office refit and had it installed today.
It’s the g4 4in1 BCHA 160/175.
We capped off the mixer outlets as I only need the hot/cold dispenser.
The unit seems to be producing a really low volume of water (much less than 1L/min). Water only trickled out the purge line during the filter flush.
Thought it might have been the filter as it was older, so the bottom was cut off. Still only trickled out the bottom of the filter during the filter flush.
Pressure is fine at the mains in and the small amount of water that does make it to the tanks heats and chills well.
Anybody have experience with a similar issue or suggestions?
Thanks

I've never heard of this item until now.
The first thing that enters my mind if possible blockage due to building up from to hard water. How's the water down under?
Have you reviewed their available manuals?
You should call or email them with your questions. Their contact information is shown at their site.

https://www.zipwater.com/shop/hydrotap/zip-hydrotap-g4-4in1-bcha-160175-classic-mixer-ht1723