It's a little hard to say from your examples, but I think you're saying that there's a constant difference in sharpness (and perhaps chromatic aberration) of any kind. one side of the frame in relation to the other.
If this is the case, it is unlikely to be a damaged coating. This is usually an off-center or slightly inclined element.
Nothing is perfect and all photographic lenses have compromises to achieve their design goals. This particular objective has sixteen glass elements in Fourteen groups. These elements allow a very wide zoom range and other features such as internal focus, image stabilization and a reasonably close focus (although not macro). All this in a package that sells for $ 200 nine.
Even the most expensive lenses are not absolutely perfect. (See this blog post from Lens Rentals on the variation from one detail to the other in geek details.) They are designed to be as close as possible to perfection. within the quality control tolerances. More expensive lenses may have finer tolerances (and are often built with more tuning capability for technicians). Low-cost lenses – and particularly complicated low-cost lenses like your super-zoom – out of economic necessity have wider tolerances for acceptable defects.
So it's not really surprising to see something that is misaligned. It is very difficult to say how bad your samples are, but you should not expect miracles with this goal. It is possible that if you had bought this new, you can send it for a warranty adjustment, but very probable that they would send it immediately with a note saying "tested: within tolerance". It is the guarantee of the camera that speaks for: Dude, it's a goal of $ 200. Our profit margin was already about $ 2. Please do not waste our time.
To learn more about inclined and off-center lens elements, see: The left side of the image is much softer than the right side: off-center lens or misfit M42-EOS?
Some people handle this problem by buying dozens of cheap lentils and turning them over until they get one that meets their personal standards. This is not very fair for your camera store, however – the economic market that the seller is negotiating with you (super-high-end zoom for peanuts) has blocked the device store photo in the middle.
My main advice is not to pixel-peep. This goal is not intended to create gallery-sized gallery prints. It is meant to take pictures for Facebook and Instagram, family vacation postcards and maybe 8×10 prints. "And even with flaws (remember, everything is flawed in this world! ), You can use it to take great pictures.
If, on the other hand, this is not what you want, I suggest spending about 10 to 20 × as much as on this goal with two or three beautiful goals of choice – it's the most economical way to achieve high quality objectives that require less design compromise and may be closer to the optical ideal.
Or, if you do not do it to have 10 to 20 × the money that burns just in his pocket, you can, like me look at the Leica S system, think "well, it would be charming, but I have to work with what I have, and I'm not perfect at this, then I will find how to get it done. " Oh, and also: you talk about "second drink", which makes me think that you may have a filter on the item before. This may very well be part of the problem – see Is a UV filter required / recommended for lens protection? on that.
Also, what image quality features make a goal good or bad? can be useful for thinking about all this.