Question about physical keyboard

So I was lucky enough to get a Priv from Selfridges in London yesterday and so far I'm loving the device. Whilst battery life is a slight concern currently, I imagine it will improve after first few days.

I do have one question for fellow priv owners though. When using the physical keyboard, if I select a text message or whatsapp message or something like that to reply to and the physical keyboard is already open, it always starts the sentence with a lower case letter. If I however were to open a message or whatsapp to reply to with the keyboard closed and were then to open the keyboard, it will start with a capital letter as I would expect.

I know to some this isn't a big deal, but when correct grammar is necessary, it becomes quite frustrating. Has anyone else experienced this and if so, any idea how to stop it from starting sentences in lower case?

Thanks!