Problems with Ipad Air 2 5th Generation and Usb C to headphone adapter

There are others here with a similar issue, and to be honest its really annoying... We use our IPad Air 2s 5th generation iPads with OnSong (great software program, allowing live performance with lyrics, audio, other great interlinking abiliities) for live performances. I only use it for audio playback of MP3s, loaded in to iTunes/Apple Music. ALL settings on both the iPad and OnSong are set to 0 or OFF in terms of EQ/Soundcheck, crossfade. When playing back the MP3s directly from the iPads built in speaker, after hitting start, the MP3 begins immediately. Problem is, that when using ANY USB-C-to-audio adaptor there is ALWAYS lag/latency that cuts off the beginning of any audio file. We perform live with tracks, and we need to hear that initial countoff - and its simply not there. All OnSong parameters are set to 0 crossfade and I find it astounding that for 10 years using my original iPad Air (with the built in 3.5mm audio output) we had NO problems. Any help from you wonderful people out there would help! Thanks... JERRY IN VENTURA, CA