This has nothing to do with your browser. It is a Swiftkey decision.
If you go to their forums (vip.swiftkey.net) you will see that, especially in flow, people are constantly complaining about this to them. They recently made some minor changes and flow now works in some areas more than it did before.
But it is very frustrating and part of the reason that I am considering switching for good back to swype - which does not have this issue