Google Maps embedding is NOT working for me

Embedding a Google Map is supposed to be super-simple, as described here:

https://en.support.wordpress.com/google-maps/

However, those instructions aren’t working for me. The only way I can (but only sometimes!) get the map to show up on the previewed or published page is to paste the html embedding code, then save the draft, and then switch to the “visual” editing view of the page — then the map is shown (only sometimes! — even those particular steps often don’t work, it’s strangely inconsistent) in the visual editing view and on the previewed or published page. However, as I mentioned, this only works sometimes, which seems odd. But what is even more frustrating: even when that procedure does work, it is only temporary, and therefore useless. After I save the draft again (whether I’ve made further changes to the page or not), the map is no longer shown on the visual editing view of the page nor on the previewed or published page. In other words, Google Maps embedding does not seem to be working as described in the link above.

Does anyone have a solution to this problem?

Thanks!