Smart Lighting (Smart App) random lagging

I have several automations setup using the Smart Lighting Smart app which sometimes run instantly and sometimes really lag (20-30 seconds).

To give an example:

I have an automation which triggers based on motion being detected on my stairway and switches on the landing light…

Sometimes the light will illuminate when I get to the bottom of the stairs, whilst other times I will get all the way to the top of the stairs before the light illuminates.

The devices I am using are:

SmartThings V3 hub
SmartThings Motion Sensors (2019)
Philips Hue colour bulb connected via a hue Bridge V2

I can see via the SmartThings app that the motion sensor doesn’t detect the motion until I reach the top of the stairs when the lag occurs but unsure what would cause the random lag with motion detection… Is it the motion sensor or a lag in reporting to the app and automation.

First question.

Go here:
account.smartthings.com > My Locations (top left) > smartapps (in the table on the right)
Scroll down until you see the SmartLighting SamrtApp, then look at the subheaders (representing each individual automation) and find the one you list above. Immediately after the automation name is it listed as ‘Local’ or ‘Cloud’ ???

It shows as local (see image below), funnily enough the one above is cloud but activates straight away everytime (this one is cloud because it has a TP-Link plug)