You have encountered one of the mysteries of equipment repair - the intermittent.
Fortunately, yours was of the "I can make it come and go through mechanical action" type. This type of repeatability gives you a fair chance of being able to track the problem down in a reasonable time and with relative ease. Note - this is not a guarantee, just a good chance. Where intermittents become annoying is when they occur in their own sweet time. Identifiable triggers make life easier - even if a bit challenging.
For example, slow thermal triggers require patience - and maybe a can of freeze spray.
However the true hair-pulling begins with intermittents that occur without any identified rhyme or reason. Those can be soul crushing. You need to apply your detective skills and have a disciplined approach to deal with these .... and sometimes the patience of Job. The frustration with these, though, is that because they occur whenever they feel like it, you are never sure that you have fixed the problem.
In your case, however, the fault was repeatable. It was also, perhaps more importantly, non-critical to the basic function of the meter, so no measurement function or accuracy issues were immediately at risk.
With the disassembly and reassembly of the unit having 'fixed' the problem, you now have that experience that most of us (if not all) have encountered. You also have the lack of knowledge as to what the actual fault was and how the disassembly and reassembly addressed that. While it feels good right now, you don't really know if the fault will return or not - and whether it might reappear in a week, 6 months or 10 years' time.
General comments - not directed at any specific product:
Bad solder joints can get disturbed just enough to make contact for the moment and the fault will come back in time - perhaps in hours, perhaps in months. Plug and socket arrangements are perhaps the best candidates for quick "repair" efforts - but even they have their quirks. If the fault was caused by some debris that was removed by unplugging and replugging, then your repair might just be permanent - but if it was through a poorly sprung pin that just happened to find a microscopically different position in the socket, then it could fail overnight ... or behave for years.
The possibilities are almost endless - and the stories are ones you generally want to be ones that others have told - but the more time you spend in this pond, the greater your chances of slipping getting dragged off the lily pad and struggling with an intermittent that simply won't give up its secret.