GG......had this problem with 4 beta 10 but have reverted to 3.6.13 and problem gone. Have not tried 4 beta 11 to see if problem eradicated.
beta 11 is the same, My version of V3.6.13 became so mangled and unusable I just uninstalled it and decided to live with the betas for a while. I'm sure they'll fix it eventuallly , I have reported it