Lighting trip will not stay on after simply turning off ?

[Aeros]

I switched the downstairs lighting trip to the off/down position with the intention to replace a light switch front to a nice brass one, but decided it was to dark so turned the trip switch back up/on straight away, but it will not stay up, I had not done anything at all and it worked fine before I turned it off,
Any ideas please, could it be a faulty trip?
Thank you

 

[ktinodia]

If you have not touch anything than:

the switch you are turning off is an rcd or mcb?
if it is an rcd than there are some brands that when you reset it, it goes in the middle position (not fully down) and than it does not reset until you switch it fully down words than in the up position.

otherwise if you did not touch anything and it does not hold, it could be also that it is mechanically faulty and sould be replaced.