The TVs have several video input sources, this should normally be defaulted to HDMI 1 which is what laptops are connected to. Some time with update this will revert to Android as being the default source, to change this to HDMI 1 or to select another source please follow the steps below.
You can also check if TV is reciving a signal from your laptop, on Step 3 there you can see there is three dots 
below inputs (Subtypes-C, HDMI, HDMI 1, HDMI 2, OPS and DP) with a connected device.
If no three dots shown then there is no output from your device which could indicate that your laptop is no connected or screen duplication/extended is setup wrong please see: https://helpdesk.cathayshigh.co.uk/en/support/solutions/articles/80001066193-duplicate-or-extend-computer-screen
Step 1
Step 2
Step 3
Default should be HMDI 1 which is what staff laptops are connected to.
