Do they start close to sync, then get farther out over time?
As, with VFR ... variable frame-rate media from phones ... drift is very common. For that, one needs typically to use ShutterEncoder or Handbrake to convert to CFR ... constant frame rate .... before importing into Premiere.
At times, drift over time occurs in other files ... where changing the length of the audio file can help "re-match" sync.
I don't know how to change VBR to CBR e..in Adobe Media Encoder, but I'm trying to use it to transcode to h264 on ingest, to see if that will fix it, since I'v3e had no problem with that format in the past. If this doesn't do it, I'll try lengthening the the audio track to meet sync points at the sart and end... Nope it did the same sync lag issue, so I guess I have to do the caveman approach finding the ratio and lengthening the audio to match.
Me isn't particularly noted for VFR to CBR conversions.
Which is why I and most others recommend ShutterEncoder for the job. Free, easy to use, handles H.264 formats very well. And you can both convert VFR to CFR, plus pick any codec you want ... from editing codecs like ProRes, DNx, or Cineform, or capture/storage/delivery formats like H.264/5 and XDCAM.