Dashboard times out frequently

I have a simple dashboard with a scheduled endpoint that calls a rest API and updates a $Cache variable every 20 seconds

A UDDynamic region on the page displays a UDGrid Container with x number of UDGrid Items (depending on how many objects are in the cache variable) each containing UDGrid Item contains a UDList of variable length depending on the properties of the cached object.

When I first start up the dashboard it loads fine but at seemingly random intervals I get the session expired popup and the page reloads. This is well short of the 25-minute timeout authentication timeout I can see Kestrel is configured with so I am pretty sure its not authentication related.

Is there some way I can determine what is causing this?

Product: PowerShell Universal
Version: 3.4.1