How can I check if the GPS of my iPhone is malfunctioning?

Years ago I activated the tracing in Google Maps and I find this feature very useful. I don't get always detailed information about the routes I travel and sometimes google Maps doesn't even detect the places where I've been, but it's generally a good reminder of my activities.

However these last months I realized that Google Maps is getting worse in tracing and often doesn't record a few places where I've been.

Of course this is a big problem if I don't check often the chronology of my days: anyway when I check I have a lot of work to do to add places and to add timing: moreover I'm very disapponted as I don't have the trace of my routes.

I presume that Google Maps receives the information from my iPhone ... therefore I'm worried because I think that my iPhone GPS doesn't work correctly or doesn't work at all from time to time!

How can I check

-if the GPS of my iPhone is malfunctioning or

-if my iPhone doesn't regularly send information to Google Maps (and why)

Thanks in advance

Alberto

[Re-Titled by Moderator]