I think an electrical fault is possibly the most likely here — in some way (that we can't tell from the extract s/t given) there was a (presumably unwanted) connection to ground / earth, which in some way might have short-circuited the command signal, for example... or given a false return confirmation of operation that had not in fact taken place.

There is also another meaning of 'grounding', that of something touching the bottom of something that it should not, such as a ship on the seabed or a screw say bottoming out in its hole; however, as a solenoid is primarily an electrical device, I think this is the least plausible scenario.

Note that 'ground' is generally EN-US usage for what is commonly referred to in EN-GB as 'earth'.