You have to go into the individual app that you are creating or downloading the file in/through and set it to save them to the card.
To be honest, setting it as "Internal" storage was not needed for this, and that may be what is confusing the phone. You only need to do that to move and run apps from the card. So for saving video or photos it would have been better to leave the card as "External" storage.
Two other things. One, video can take up a serious amount of space. Way more than one thinks. So having turned the card into "Internal" storage can also be a curse, since that card will only be readable by that device, and only if the device is as it is now. If you tried to "Hard Reset" the device at any point, everything on that card would be lost.
Two, you won't be able to swap out SD cards like you can with them being their standard "External". Once that card was encoded to the device, now you either won't be able to encode another card, or you will be able to but then lose access to the original card.
So, in any case, if you can run your apps fine off the phone's original storage, I would suggest that and leave the card as "External" storage. Then set up the apps (like camera) to save to the card.