Lumia 950 XL text input doesn't work AND mobile phone is overheating

I sent feedback on this to MS using both mobile phone and a desktop Windows 10 computer. I wanted to share my obscure experience also on this site. Sorry if this forum is not meant for mobile issues. To put it briefly: Finnish keyboard gets Lumia to overheat and causes text input to accept only one word. This does not happen with Swedish or US English keyboards.

With the new Aug 31 release, comma and space break text input in SMS and applications. I cannot write more than one word in messages if I start with a letter. If I start with a point (full stop) and use the point sign instead of space (between words) I can write several words. Comma does not make several words possible.

At first the new mobile version worked fine and e.g. Cortana worked as expected. In the morning I adjusted some text scaling and/or display item size settings and after restart the phone started overheating and the text input was broken. Several restarts and scaling text size back to normal did not resolve the issue.

This OS is Windows 10 mobile 1607 and build 10.0.14915.1000. If I use Cortana speech recognition I can add words after the osd keyboard stops sending text input to the text field. I have tried this in Outlook mail, SMS and some IM applications. Only if you add a point before each word and don't use commas or spaces you can write several words. Pasting text (several words) works if the bug is not yet active.

It is possible, though, to add an emoticon (in an IM app) after the text input stops working after which it is possible to add a word or with point characters several words. But in SMS it won't work.

I reset the phone to factory settings TWICE and the problems persist. It seems that If I use Finnish keyboard text input the text input breaks. The first reset was into Finnish and the text input failed. Both resets yielded the 1607 edition of Windows 10 mobile with 14915 build even though I thought they would have reset the device to an earlier build. Probably I will need to reset the phone using PC mobile recovery software.

The second reset was into US settings and English and with that the text input worked well at first. After starting to write in English I could no more write more than one word in a text field. If I switch back into English layout the input still fails. The phone needs to be rebooted to restore text input functionality.

I can write these Finnish special letters and with a Swedish keyboard - the text input does not fail - but if I switch to Finnish the input functionality breaks and I am only able to write one word in a field.