I had one of these a while ago and it was very good in all ways , especially the build , as you say .
It may be , by the looks of it you have a bad example ?
I have since sold mine and saved my pennies and got a 90mm Takahashi SKY90 and its f 5.5 is the same as the LP but the Flourite lense element is essentially perfect , zero CA or any other problems .
If I was you I would return it and ask for a replacement .
As I said mine was not perfect , but it was good . Better than what I see in your photo , thats for sure . These LP's have FPL51 which is pretty darn good glass .
It boils down to , if you want the best ,, " You gotta be prepaired to pay for it " sad but true
.
Send it back as it aint right .
Or as said here get an 80ED .( I have had one of these as well , great scopes , abit a little basic but awsome FPL53 optics )
Brian.