Captions burned in despite sidecar option turned on

I am trying to help you. Can you provide the project and media, and exact repro steps? I can send you a private message with the instructions in this forum.

Did you try a newer version? Did you try with "Import sequences natively" turned on and off? Did you delete your media caches?

When I export my timeline from Premiere, with captions - scc - I send the media to Encoder to export the media as MXF with Captions. I select Sidecar for the Captions and Encoder burns in the captions on the video file. I tried to copy and paste the timeline and create a new sequence and tried it again, but the same error occurred. Now I have to export my media file straight from Premiere, which ties up my editing. I have reached out to Adobe for tech support, but no one has been able to replicate the problem or suggest that there is a problem. My conversations with tech support abruptly ends and no solution is found. This all seemed to happen after the last update of Encoder and Premiere. 

I have the exact same problem. When exporting from Premiere Pro, captions are saved in a separate file and are not visible in the video. But in Media Encoder the are visible in the preview window and  are visible in the exported video as well.

I was not able to repro your issue. I added captions and exported to mp4 and sidecar srt and sent to AME. The result was aclean mp4 without buned in captions and an srt file, like expected.

Can you share your project for me to look at? I can private message you the instructions if you are willing and able to share.