Have an odd issue with my trekking, noticed the drivers side headlamp was out (no warning on dash) had a look and fiddle getting bulb out, then, as I had no spare I put it back and it worked! This was ok for a while, then noticed it had gone again (no warning on dash) by this time I had found spares so went to take bulb out and it again worked! however after pulling away and on a short journey I noticed nearside bulb was out, anyone had this and what was the solution? Cheers, John

There is no warning for the headlamps - it only tells you about bulbs you cannot see yourself, such as DRLs, numberplate, rear fog, and brake lights. It doesn’t tell you about indicators either as they will flash faster if a bulb goes.
As to the issue... my 2013 4x4 had a problem where the ‘tags’ on the bulb were badly soldered, which led to the plastic of the wire connector melting as the high current tried to pass through the poor connection. Maybe worth a check?

More than likely just a bad connection and as stated the computer doesn’t tell you when a head light bulb is out.

Sometimes it can be a bad joint in the bulb itself so a change of bulb may fix the problem anyway

something similar happened to me a while ago - but yesterday the bulb went again and was kaput on inspection when removed. Have a spare handy.
PS have just sent off for some phillips +130% H4s - with which I am sure I will melt the tarmac! not to mention any snow we might get!