repeating video but continued audio

Im Beginning my youtube career as a fitness influencer and im finding it really hard to edit my videos because for some reason when i import them they are glitchy but when i watch them back as raw clips from my desktop theyre fine? and example of this is that i could be midway speaking in the video and then its would jump back to the beginning of the video but then continue the audio as if the video is still playing at normal time? if someone could please help that would be much appreciated !

P.S i tried making proxies aswell but it happens for them too!