Make sure slots and RAM contacts are free of dust and not damaged etc.
Try different slots with the new RAM.
In theory, any DDR3 8 GB RAM module should work with your motherboard. However due to variations in component tolerances (motherboard and RAM), it is possible that the tolerances are too far apart between the motherboard and RAM so that they don't "communicate" properly which leads to problems. Basically the RAM may be incompatible with the motherboard.
If possible check the new RAM in another system and see if it works. If so, then the RAM is probably OK and it is a case of incompatibility between your motherboard and the new RAM.
Motherboard and RAM manufacturers usually publish lists of tested compatible products that should work with each other.
According to Asus
HERE, the only compatible single 8 GB RAM modules are from A-Data and Samsung. But the RAM manufacturer should also be consulted to see what motherboards are supported by this new RAM.
Note. If compatible RAM and motherboards are NOT listed at the respective manufacturers websites, this does not necessarily mean that the components are incompatible. It may be just that not all component combinations have been tested, as there are literally hundreds of possible combinations and it is time consuming (and expensive) to test all components.