This used to be very common back in the day before gated shifting. If you look at the shape of the chainring's teeth you can imagine what's happening. If the chain hits the ring with a roller to the tooth tip and you spin the crank because there's no load, the teeth will skitter below the chain keeping it out at the edges of the teeth. It's like shifting an auto transmission with the engine RPM not matched closely enough -- gr-r-r-r-i-i-nd.

A contributing factor could be chainring separation. If the chain is a bit too narrow for the crankset, (ie 10s chain, 9s cranks) it can lean against the outer ring with the plates lined up to the chainring teeth, rather than moving over so it drops in.

Also if you have unmatched chainrings, or don't have the little diamonds lined up properly the chain is more likely to land out of phase making your problem more likely.

The FIX,

1- check chainring gap, and/or chain width. test by putting the chain against the inside fce of the outer ring and see how it lines up.

2- check phase marks and rotate the inner ring to a new position if necessary. Test by hand shifting the ring through the outer ring's gate and seeing how it phases as it comes in contact with the inner ring. If it lands roller to tooth, rotate the inner ring to a new position. There are 5 positions each 1/5th tooth apart in phasing, so one will be close.

3- there are no synchro rings on bicycles, so you have to help the chain engage by timing you shifts and easing power off for a 1/4 second so the chain can engage. This is learned technique like toeing the clutch for a fast 2nd to 3rh shift in your car. Once you get it down it'll be second nature and you'll never think about again.