If you have a IGPU HD7340 then you either must have a E1 or E2 Desktop or Laptop APU AMD Processor. Both seems to use the same drivers: https://www.amd.com/en/support
I checked both the Desktop and Laptop versions and both shows that AMD doesn't support that APU with driver updates anymore. It is considered to be legacy. In fact AMD doesn't even have Windows 10 drivers for that old APUs.
So unless Ubuntu updates the driver themselves the only choice you have is trying to install the Ubuntu 14.04 Driver or see if you can try and make it compatible with the latest version of Ubuntu.
Go to this very good Linux Forum website called Phoronix (https://www.phoronix.com/forums/ ) or Ubuntu Forums (Ubuntu Forums ) and post your question there and see if anyone as a similar issue or could advice you on how to make a legacy driver to work on the latest version of Ubuntu.