some of my entries return NULL entry meta (post ID, user ID, e-mail) in the gf_entry table. The data is missing only for a few entries. Missing email also means that Gravity Form cannot send the e-mail notification. My forms are only shown for logged-in users, so I’m not sure what could be the issue here. Could this be a server-side issue?
To help troubleshoot the issue you’re having, we need to see what’s going on behind the scenes with Gravity Forms, which means we need your logging enabled.
Please enable logging by going to Forms → Settings → Logging. Select: On and Save Settings. (documentation)
Replicate the Issue you’re having so it’s recorded in the logging. In this case, try your form again or wait for an user to replicate the issue.
Leave logging enabled until the issue is resolved and you no longer need our help.
Once the issue has been replicated, submit a support ticket, and include the system status report with the logging links included. (documentation), and the entry ID number for the logged entry where he issue happened.