Hint and autocomplete displays help for wrong parameter

Description

What steps will reproduce the problem?

Enter the following code into an empty editor

class Foo:
    """my documentation here"""

    def __init__(self):
        """doc2"""
        pass

class Bar:
    """I'm a bar"""
    pass

def nada(foo: Foo, x: Bar, y: Bar):
    """ nada thingy """
    pass

def a(foo: Foo):
    nada(foo, t

Now with the cursor at the t at the very end, type a period. This pops up a hint balloon, but it displays the help for the class Foo, "my documentation here". The autocomplete window displays the choices foo, x, and y - the parameter names of nada. It doesn't make any sense to complete t. with, for example, t.foo or t.x, but these are the options provided to me.

This is a super simplified example of what I'm seeing regularly. I'm passing variables in in the form var.attribute, and when I type the period it shows me the documentation for the first variable in the parameter list, and the autocomplete list is well, long and not related to the parameter I am trying to enter.

This is the simplest failure case that I can generate based on my real code base.

Versions

Spyder version: 4.0.0b5
Python version: 3.7.3
Qt version: 5.9.6
PyQt5 version: 5.9.2
Operating System: Windows 7

Dependencies

cloudpickle >=0.5.0          :  1.2.1 (OK)
pygments >=2.0               :  2.4.2 (OK)
qtconsole >=4.5.5            :  4.5.5 (OK)
nbconvert >=4.0              :  5.5.0 (OK)
sphinx >=0.6.6               :  2.1.2 (OK)
pylint >=0.25                :  2.3.1 (OK)
psutil >=0.3                 :  5.6.3 (OK)
qtawesome >=0.5.7            :  0.5.7 (OK)
qtpy >=1.5.0                 :  1.9.0 (OK)
pickleshare >=0.4            :  0.7.5 (OK)
zmq >=17                     :  18.1.0 (OK)
chardet >=2.0.0              :  3.0.4 (OK)
numpydoc >=0.6.0             :  0.9.1 (OK)
spyder_kernels >=1.5.0;<2.0.0:  1.5.0 (OK)
qdarkstyle >=2.7             :  2.7 (OK)
atomicwrites >=1.2.0         :  1.3.0 (OK)
diff_match_patch >=20181111  :  20181111 (OK)
watchdog                     :  None (OK)
keyring                      :  None (OK)
pexpect >=4.4.0              :  4.7.0 (OK)
pympler                      :  None (OK)
sympy >=0.7.3                :  1.4 (OK)
cython >=0.21                :  0.29.13 (OK)
IPython >=4.0                :  7.8.0 (OK)
matplotlib >=2.0.0           :  3.1.1 (OK)
pandas >=0.13.1              :  0.25.1 (OK)
numpy >=1.7                  :  1.16.4 (OK)
scipy >=0.17.0               :  1.3.1 (OK)
pyls >=0.28.2;<0.29.0        :  0.28.2 (OK)
rtree >=0.8.3                :  0.8.3 (OK)

spyder-ide / spyder