Exported video quality lowered on phone but okay on computer.

Hello! I haven't noticed this problem before though this is a longer (stop motion) video I've made and I've included sound for the first time. The beginning of my video looks blurry but the rest is okay. I am exporting a 20 second video with H.264, "match source" and VBR, 2 pass as the settings and I have tried various bit rates (between 6-10) Have you encountered this before? Are there different settings better for Instagram when viewing on a phone?  It looks fine after exporting on my computer but the quality is lower when sending it to myself in a message. Thanks!