Vinyl Installation Window Question

Inspected home built in 2016 with vinyl widows installed and Fiber cement siding. Windows appear flush with siding on sides and bottom, but there is a gap at top.
Should this area be caulked? Does it appear to be installed correctly? If appropriate house wrap, tape and flashing are installed would this be a problem?
Is it the appropriate window to be installed with Fiber cement siding?
A lot of questions… but looking for answers/suggestions.
Thanks

Why windows leak in new construction Houston homes

It appears that the required head flashing is missing. No, caulk cannot serve as head flashing.

1: The manufactured framed window was not flush/parallel to the framing.
2: The window is not flashed properly. The term, cap flashing. Typically/usually cap flashing extends >< 1.25" inches on both sides.
How to install flashing around windows and doors.
Great inspecting by the way!

Those windows are made with the an optional exterior window trim. Those are designed for that trim piece to function in place of a j-channel, primarily for vinyl siding installs. What you don’t know is if the MRB was set correctly and sealed over the top flange, you have to hope so. No, that would not be caulked, water is supposed to flow down and out of that channel.