Bosch integrated SGV59T03/07 faulty

Hi
***just found salt reservoir full of dirty water if that helps ***
For a while plates were not clean, then tablet found undissolved, noisy banging pipes when dishwasher tureen on on. Discovered that dishwasher was not filling and drain pump wS running a few secs after door opened. No leaking apparent with unit in situ. Checked drain impeller and rubber ‘dongle’ – all fine. Reset dishwasher and it filled and worked fine for a day, now problem is back. It gets to ejecting tablet but constant pulsing sound as if draining. Is this most likely to be fill valve issue (but why did it work after I fiddled), flood switch, hidden flood in base, control module or something else? Ps is there a test cycle on this model? Cant see how to run it.

Thanks