/e/OS technically can’t guarantee Google-dependent Apps (not only Apps by Google) to work all the time. /e/OS can only do its best, which at times might not be enough.
So, whatever a possible solution might be in this case, you either need an alternative maps App to use in such times anyway, or you chose the wrong OS.
The closest thing to the Google Maps App I’ve seen so far should be GMaps WV, which is just the Google Maps website wrapped into an App. You could, of course, use the Google Maps website in a browser, too.
Alternatively, you could have a look at Magic Earth (preinstalled in /e/OS as “Maps”), at Organic Maps (mentioned quite often) or at OsmAnd (quite popular because of all the features, but not everybody’s favourite because of all the features - go for OsmAnd~ with the tilde if interested, it’s the unlimited OsmAnd+ version from F-Droid).
If you just wanted to have the highest chance of Google stuff to work on a non-stock OS, then you should be on LineageOS with GApps installed and your device registered at Google for the legitimate use of GApps on an uncertified Android OS (https://www.google.com/android/uncertified ).