One thing you can try is to check the raw log data, using the /jl command. Specifically, open a browser and type in:
http://x.x.x.x/jl?pw=yyyy&hist=2
where x.x.x.x is your OpenSprinkler’s IP address, yyyy is the md5 hash of your plain text password (you can use an online md5 hash calculator such as https://www.md5hashgenerator.com/ to get it).
Check the output and see if there is any obvious problem.