‘Clean Pump’ Light Whirlpool AWO/D 4505

Hi – Apologies that my first post is one begging for help – it’s quite selfish of me, I’m aware!

I’m getting pretty desperate now though – my washing machine is acting extremely strange.

At the end of a wash cycle the water drains from the drum in 2 stages (this is when testing on quick wash mode):

Stage 1 – The bulk of the water is quickly drained out of the tub without any issue.

Stage 2 – a pulsating noise from the pump. it sounds like it’s turning on and off once a second. Maybe very slightly quicker than that.

After doing stage 2 for about 2 minutes – the clean pump light comes on.

This is odd to me as there is nothing obstructing the pump. I have remove the filter and all is clear. I have had the drain pipe off of the pump and completely cleared this of gunk and debris and I have remove the pipe from the tub to the pump to ensure that was free flowing too.

I am all out of ideas and it is destroying my soul – could anyone point me in the right direction? What should I check next? Does the drain pipe have to be set at any specific angle to avoid air locks?

Thanks!