Data loss ("bad request") in JATOS
I am currently running a lab.js study on JATOS and 25% of my participants are reporting that they clicked on submit at the end of the study, but got the error message: "bad request". Data is also missing for these participants. This has happenend to maybe 1-3 participants in earlier studies, but never to this extent.
I have tested the study many times on different browsers (firefox, chrome, edge), but could not replicate the error. In additoin, I have run other studies on the same server without problems before. I would be thankful for any pointers on what is going on and how I could reduce data loss for my study.
More info: JATOS version 3.4.1 on DigitalOcean with Traefik, individual data size 5.0MB