In some cases in can be helpful to collect the browser logs to facilitate analysis.

Activate the browser Developer tools

Press the key F12
   or
go to the menu More Tools/Developper tools
   or
the key combination Strg + Shift + I

Save the logs

Two type of logs can help the analysis. Console logs and Network logs.

Reproduce the issue and then save both of them.

Console logs

Save the log file (e.g. web.openrainbow.com-1561713163213.log)

Network logs

Note: do not forget to activate the option "Preserve log" before reproducing the issue.

Save the HAR file web.openrainbow.com.har