Win 10
Calibre v 5.2
Since upgrading to 5.x have been having the following issue
I use the search & other features regularly but since upgrading to Version 5 the time to display the dialog box to use it is
painfully slow.
On click, no apparent response for 4-5 seconds then an indicator that [library name] is not responding then the dialog pops up ( and then works without issue for all functions) almost immediately after not responding notice.
Searching by just typing into the search bar works without issue
Issue is new since upgrade
Otherwise responsiveness of Calibre is 'normal'

What could be causing (& possible fix) the delay in displaying the dialog ?
TIA