Go to Declaration stops working for .robot files

I have PyCharm v2018.1.4 (Community Edition) installed on Windows 10.

This issue is specific to .robot files.

I noticed that Go to -> Declaration OR ctrl +B works fine initially on methods called in a .robot file. But as I continue to use the tool or run some tests etc.. the navigation just stops working.

The keywords are not highlighted anymore, it stops auto-suggesting method names and stops navigating to the declaration for any method defined in the referred Library in Settings.

Further, if I restart pycharm, then again it starts recognizing the methods and Go to Declaration works again up to a certain point. The behavior is random, meaning I have no specific reproduction steps for it, except to say it occurs definitely.

Since it does work for some time, the right plugins are installed are a given. Also the tool and all plugins are up to date.

Please advise.