I'm also having the same problem with the same configuration: Ubuntu 18.04.2 and GNOME 3.28, but the solution of Fabrizio Bertoglio (fabriziobertoglio) #28 aliviated the problem.
I'm also having the same problem with the same configuration: Ubuntu 18.04.2 and GNOME 3.28, but the solution of Fabrizio Bertoglio (fabriziobertoglio) #28 aliviated the problem.