Camera to Lightroom Mobile to Instagram - degraded quality

Hi everyone, First time poster here

I don't have a laptop small to bring with me on my travels so I rely on Lightroom mobile for editing. What I've found is that when I upload to Instagram from Lightroom mobile, the quality of the photo drops off significantly (possibly worse than iPhone 6 quality). However, I don't experience the same drop off in quality when editing the same photo on Lightroom on my laptop. With this workflow, I import the photos to Lightroom on my laptop and send it to my phone to upload via iMessage. Some additional info:

1. I shoot with a Sony a6000.

2. I use a SD lightning adapter to import my photos to my iPhone 6 / iPad mini.

3. I experience the same issues with jpg and raw.

What are your your preferred ways for post processing and sharing on the go?!