Autocompletion and type/method signature checking does not work after the second degree inside of an is block

[Synzorasize]

Tested versions

v4.4.dev7.official [46c8f8c]
master [5b52b4b]

System information

Godot v4.4.dev7 - Fedora Linux 41 (KDE Plasma) on Wayland - X11 display driver, Multi-window, 1 monitor - Vulkan (Forward+) - integrated Intel(R) UHD Graphics 620 (KBL GT2) - Intel(R) Core(TM) i5-8250U CPU @ 1.60GHz (8 threads)

Issue description

When using object is [class name], autocompletion does not work after the second degree property/method access, and neither does type/method signature checking.

Example:

var node3d := Node3D.new()
# Gives argument error. (Correct)
node3d.position.direction_to()
node3d.quaternion.angle_to()
# Gives no error. (Correct)
var x := node3d.basis.inverse().x
var y := node3d.transform.origin.y

var node: Node = Node3D.new()
if node is Node3D:
	# No error. (Incorrect)
	node.position.direction_to()
	node.quaternion.angle_to()
	# Gives inferred as Variant error. (Incorrect)
	var x2 := node.basis.inverse().x
	var y2 := node.transform.origin.y

Steps to reproduce

Inside an is block (use any subclass), access a property/method that returns a math/collection/Object type Variant from that subclass, then access a property/method of that returned type. No autocompletion will appear for the third degree, and no type/argument checking will work for the second degree. When assigned to an variable, it will be inferred as Variant instead of what the property/method returns.

Minimal reproduction project (MRP)

autocompletion-is-issue.zip (same code as above)

[Synzorasize]

It looks like #84264 fixed the autocompletion aspect, but the type/method signature check is still broken.