Polygon-Werkzeug

AI may be a hot potato but that has nothing to do with your comments about it in this thread.  The polygon lasso tool has been around since the birth of the program - or at least since Elements 4.0 which is the earliest version I have on my computer.  I can't imagine that any AI which has been incorporated into Elements in the past few versions has anything to do with your original problem of being unable to complete a desired shape.  So, no, I don't think anyone will comment on an AI conspiracy theory without some reliable evidence.  And while you may not be the first to report this issue, it is an extremely rare occurrence.   My own current speculation is that it has something to do with your mouse or your mouse settings or handling. But that is a pure guess on my part and is no more valid than your speculation about AI (whatever you mean by that).

However, to alleviate your concerns about Adobe interfering with your work, you can go to the Account and Security>Data and Privacy Settings tab of your Adobe account and, if you have not already done so, you can turn off Adobe's access to your usage of the program and your content analysis:

The Lighting Angle issue has to do with whether Global Light is on or off in the Layer Style. Something that unfortunately cannot be turned on/off since photoshop elements 5.

The Drop Shadow, Inner Shadows and Bevel Layer Styles in the Effects>Styles panel have Global Light always turned off

The Drop Shadow and Bevel Layer Styles you get from going to Layer>Layer Style>Style Settings always has Global light on.

What the photoshop manual says about Global Light in layer styles

" Use Global Light

This setting allows you to set one “master” lighting angle that is then available in all the layer effects that use shading: Drop Shadow, Inner Shadow, and Bevel and Emboss. In any of these effects, if Use Global Light is selected and you set a lighting angle, that angle becomes the global lighting angle. Any other effect that has Use Global Light selected automatically inherits the same angle setting. If Use Global Light is deselected, the lighting angle you set is “local” and applies only to that effect. You can also set the global lighting angle by choosing Layer Style > Global Light. "

The only other suggestion I have is to do a complete uninstall/reinstall of the program.  When uninstalling use the option to delete the Preference files.  In the meantime, you can try using the Pencil tool:

Under Edit>Preferences>Performance, try turning off the Graphics processor:

@Walter296382640jlj glad the problem has been resolved.  But when you reply via email, we cannot see any images that you have attached to the email.  Nor does a reply notification email contain any screenshots that have been posted on the forum.

And what version of Elements are you using?  I had no trouble creating a polygon over an Elements graphics template at the top edge of the workspace.  If you are unable to do this, try resetting the Polygon Tool, using the dropdown menu at the right of the Tool Options panel.  If this is not the problem, we need a better description from you and a screenshot would be helpful.  (Something may have been lost in translation.)

What version of Photoshop Elements and operating system are you using?