Paint bucket tool really slow in Painter 2019

Hi there,

The paint bucket tool is really really slow, if I go from any tool that I am working with then choose the paint bucket tool it takes ages to register that I want to use it about 20 seconds of the spinning coloured wheel. 

Just wondering if anyone else has this issue. All other tools work fine.

User system iMac OS X El Capitan

Many thanks

Linda