Yes, it’s possibly related. I’ve just posted a script that can be used for diagnosing certain firmware issues:
https://opensprinkler.com/forums/topic/useful-script-for-testing-opensprinkler-api/
you can try the ‘Json log (jl)’ API, start with ‘Today’, then go back to 1 day, 2 days and so on. It’s possible that at some point the json log data gets truncated, becoming invalid. If the 2K theory is correct, you can check the number of characters in the log data at that point and it’s probably more than 2K. Updating your firmware to the Jul18 version should fix this issue.