that keyboard issue is known, not sure if there is a fix yet but the workaround is that you select another keyboard as the default to get the keyboard to show again, and don't use the speech to text feature for the time being....
which keyboard were you using?
also, as notforhire noted, it is a massive update... so you may need to either reboot or cache clear to remove any old data left on the phone. also a lot of settings change have been reported so keep an eye out for changed settings.
for each app, it can be done by either going to the settings > apps > select the app of interest > storage > scroll down to see cache clear.
Or you can hold the app icon and click the " i " for that app setting and find the storage > cache clear.
for the whole device's cache partition clear, power off > hold vol.up + powerkey ~7sec > using the vol key scroll down to cache partition clear > select by pressing power key > once you cleared it, reboot normally by selecting the very 1st option (you'll see the reboot normally option).