I can tell you that when both my Canon RP and 5DIV were new they arrived needing updates that made a difference in their performance.
Never assume that the "New" product that you receive is up-to-date.
Thanks for sharing this info Larry, and
Smile,
JimmyT Sends
Bravo Zulu

Go to: https://www.usa.canon.com/internet/portal/us/home/support/drivers-downloads
Select your camera and click on the "Firmware" tab. T6 and T6i currently have updates. The T6s does not. Select and download to your computer the most current update. You only ever need the most current one, not every one that you may have missed. There are 2 versions of each, depending on what operating system is on your computer. These are Zip files so once on your computer they have to be extracted. Once that is done you will see a file folder and a lone file. The folder contains instructions in various languages. The lone file gets loaded onto the memory card in your camera. Before loading do an in-camera format of your card. Then put the card into your card reader and put the file (not the folder) onto the card. Just place it on the card. Do not put it into any of the folders that will be on the card. After that just put it in the camera and you are ready to start the update as per instructions from the folder. When finished re-format your card and you are good to go! The whole process takes less then 10 min. Make sure your battery is well charged.
BTW, Canon does not supply updates for any lenses except Canon. If your Tamron is capable of being updated you will need to contact Tamron for details and you will probably need a docking station.