There are a lot of smaller issues going on here, we can try to address them individually. The solution of "make unique texture," won't work here, but I can explain what it does and where it would work.
The first thing you want to do is to remove all textures and examine the model in Sketchup. You will want to insure that the exterior is smoothly composed of all white, or all light blue polygons. These colors define the front and back sides of polygons and each side renders textures differently.
This image shows evidence of polygon reversal.
It appears you performed an extrude operation on the vents, or windows and pulled a few polygons out from the rest of the exterior and the newly created polygons arbitrarily selected reversed orientations. However, there are geometric irregularities in this image, that are not present in the model shown in the MCX viewport image, it is extremely unlikely that both images represent the same version of the same model.
I'd like to comment on the predominant texture that is visible. Sketchup has the capacity to both photographically project and tile textures, it can do both in the same model, but only the mapping for one type of projection can be compiled into an MSFS model. Photographically projected textures are just what they sound like, it is as if a photograph was placed into a projector and shined onto the model. Tiled textures are also exactly as they sound, it is as if someone took a tile made from the texture and sequentially stacked that image across the face of the model.
Tiled textures are really nifty in Sketchup, one can take a model of a wood house, touch the model with the wood tile texture applicator and voila, realistic looking wood house. If that seems too easy, you may be a master modeller. Photographically applied textures is where, imo, Sketchup shines as a true extension of one's creativity.
Here is an example of a model that I textured in Sketchup using a projected photograph. You are welcome to download and examine this and any of my models using the link in my sig
You can see the photograph has been edited to make it easier to project onto the model. Near the tail, reversed versions of the markings have been placed so the model can be displaced horizontally during the projection procedure, in order to place the properly oriented markings on the tail, depending on which side of the model is being textured.
A common side effect of using tiled textures in Sketchup, is that modellers distort their projection and force the creation of a new texture. This is where the "make unique texture" rule comes in and I consider that to be a band aid solution. First off, "pouring" a texture onto a model to be perfectly spaced and laid out, like bricks, is kind of a step saver, it is going to have the potential to lay a lot of brick/tile images with little effort and possibly have some fitting issues. Next you come along with another step saver, "make unique texture" and you've thrown a band aid on the whole fitment issue. I personally try to stay away from the idea of making a model more complex, as a consequence of making it easier to create and try to stick with making a model more complex, if doing so provides a more immersive experience.
One easy rule to remember is to "never move the yellow pin." When aligning a texture in Sketchup, there are three scaling pins, overall scale (red), height scale (blue) and width scale (green). The yellow pin is the skew pin and helps to shape the texture to mimic the effect of contouring over a curved complex surface. The mathematical calculations required to place the skewed version of the texture cannot be stored in the model and if a new texture is not created that will "naturally fall" into the calculated position of skew, from the original texture, then MCX will encounter all that weird skew texture telemetry and simply assign the default version of the same texture to the polygon upon compile.
Another possible way the skewed texture gets assigned, that I have not researched, is when the extrude operation is performed on textured polygons and new skewed polys are created from that process. To address this, you would want to review grouping, locking and isolating procedures, that allow you to edit specific parts of a models geometry without affecting other parts. This would allow you to, for example, increase the depth of the vent/windows, without pulling the skin of the model with them and consequently making the odd chevron shaped extrusions above them.
There are some odd quirks about Sketchup that bear mentioning here. If you texture a locked model, a tiled version of that texture will cover every backside polygon that was previously untextured. I have encountered render issues with polygons that are textured on both sides, so I am very careful and beyond that, there is the simple render issue, of doubling demand by drawing polygons that are not seen. In the first image above, the polygons that appear to have been reversed by the extrude operation are already covered with a contrasting texture. This suggests that the interior of the model, the backsides of the polygons, have had that texture applied to them.
If that is the case, the only way to clear the undesired texture assignments is to open the model in Sketchup, delete that texture from the model, then carefully reintroduce it and apply it only to visible polygons.
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