Constant audio sync issues when exporting from Premiere Pro

[terminusnyc]

I've seen various reports about this but nothign totally concrete.  This never used to be an issue for me but as of the last maybe 6 months, I'm having constant sync issues when I export video from Premiere Pro...it's generally Iphone HD video, but the issue occurs with various settings in the export - if I use ProRes or HVEC 265 - if I do hardware or software encoding - and if I use High 10 and 2100 or not...I'm really not sure what's happening, and this doesn't happen if I use FCP instead (but I hate working in FCP).  I'm going to post a dropbox link with two versions of the rendered video - one with the audio 2 frames forward and one in sync...because I'm always working with musical artists, the syncing is crucial.  I'm starting to wonder if there's something wrong with my MBpro?  I can even send someone the raw premiere files if they might be willing to check it on their end.  I'm just at my witts end with this.  

https://www.dropbox.com/sh/x1ko1borqea8dks/AADJIdXUwljSyMw0b2zKCMVoa?dl=0

I hope there's some solution to this nightmare.  I've worked with HD video from iphones for a few years and never had this issue before.  

[R Neil Haugen]

Perhaps the files with trouble are VFR, variable framerate? If so, converting those to constant framerate in say ShutterEncoder then replacing the clips in the project w converted CFR clips would help.

Neil