Running Premiere Pro on the laptop with the specs as listed is going to be rough.
CPU is only dual core at 2.7/3.5ghz. Ideally, you'd want at least a quad core or higher especially dealing with high-res 4K video. With a hexacore i7 4.2ghz system, my system already struggles depending on what I edit in Premiere so I can't imagine what performance is like with a dual core i7. You must have a ton of patience.
The NVIDIA 940mx scores pretty low on most benchmarks and is another bottleneck. It is more of a mobile GPU designed to be efficient in terms of power consumption and not known for its performance.
8GB of memory is a very minimal amount when editing videos or creating any type of multimedia content. The OS will typically consume ~4GB so that really leaves you with 4GB remaining for all other processes and applications. At times, depending on the project, Premiere Pro consumes > 10GB alone so there is likely a ton of swap file activity going on further degrading performance.
A new laptop (or system) would be the best route to improve the experience and efficiency in editing videos. The Zenbooks are super nice but were not built for video editing.
