But Bruce has given you two very good bits of advice.

The idle speed could simply be too low. Will it sit at idle for 30 seconds? It should. Does the idle taxi the airplane? It shouldn't. But it can be increased until it will and then backed off a click or two and the reliability in flight should improve.

And the engine should go to WOT from an extended idle without skipping a beat. If it won't, THAT's when the lowspeed should be tuned. (We say "the lowspeed should be tuned" when we don't know if your engine has a needle or airbleed for that tuning. If somebody told you to adjust your lowspeed needle, what'd you do? You ain't got one.)