Beko dishwasher not draining?

I’ve got a BEKO DE 3431 FW dishwasher that is playing up. Yesterday morning, the dishwasher part finished an overnight intensive wash cycle with water left in the bottom of the washer – can’t confirm if the end light was on or not as the missus turned it off before I saw it. So turned the machine back on and it started to drain. After a few minutes all u could hear was the drain pump (?) continuing to hum. Regardless of changing the wash cycles, turning off and on etc, the humming continued. After a bit of online research, I tried the ‘tilt backwards’ trick and sure enough after tipping out some water in the bottom tray (which obviously activated the anti-flood switch), I selected a cycle and the humming had stopped but my consumer unit tripped after a couple of minutes. Took the machine outside, stripped the sides, bottom and front plinth for visibility and dried what I could (as I assumed the short was occurred from the original leak). I noticed the bottom door seal looked dodgy so I took it out and reinserted it. Spray arms were not blocked and filters were all clean. I opened up the water softener but only water came out. I then did a couple of test washes, looking for more leaks – first a pre wash which ended but it didn’t drain (never used it before so was unsure if normal) then a rapid wash. Got all the usual noises inside so the arms were spinning etc but the machine wouldn’t drain. So I interrupted the cycle and scooped out all the water and tried another rapid wash. Its just finished - no leaks, but the spray arms hardly moved this time, the impeller (?) on the bottom right side was turning and the washer filled up OK. No drain though – so the bottom of the machine is full of water. Any ideas?