Lots of home DVD recorders can record in two formats.
One is the standard DVD format so that your recordings can be played in any DVD player and the other type is a proprietary format specific to the DVD recorder (this format usually offers more features).
Two things to check - Look at your instruction manual to ensure that your are recording in the format that’s compatible with most DVD players. In the case of my player (Pioneer) it's called Video mode.
Make sure that you finalise the recording that you have made.