Scammed?

The Adobe community support forums home address is 

https://community.adobe.com/

But when you click on it to login, what you're getting is a redirect (or forwarding address) to the main user account authentication  login screen. It results in this page being displayed:

When you select a login method, you will notice in the image below how at the end of the URL it ends in : "_flow_type=login# " (without the quotes).

That URL belongs to the screen where you initially enter your AdobeID or account username. 

When you proceed it redirects to another redirect screen where you are prompted for the password associated to that AdobeID, like shown below, and notice at the end of the URL string, it changes to =login#/password which is the second part of the authentication process 

As you continue to navigate into the forums, you will notice in your browser  that it change quickly a few more times until finally gaining access to the main support forum landing page.

So the last address that you should see in your web browser is

https://community.adobe.com/ 

Which belongs to this screen

Or like the one below if you're viewing your user profile 

https://community.adobe.com/t5/user/viewprofilepage/user-id/ 

And everywhere you click to forward your browser requests  inside of the community forums will look like the last address above and like this one

https://community.adobe.com/t5/acrobat/bd-p/acrobat?page=1&sort=relevance&filter=all 

Which in return will redirect users to this discussion thread when they click on the link you posted, shown below

https://community.adobe.com/t5/acrobat/scammed/td-p/10881236

See image once more:

The page long URL that I posted in the images are supposed to bring you here, not to a PDF Filler website.

You must've been tricked into clicking in another website by  following the instructions of a scammer, OR, your browser has not enforced an ad blocker add-on (if you had one), is prone to WebRTC vulnerability because is not disabled (see here: Restore Privacy  ), and probably lack of important updates applied systemwide.

So in short, as far as the web browser behavior that you're experiencing,  looks more to me like browser hi-jacking which is  not the same as getting scammed.

But the conniving tricks played on gullible consumers to have them click on fake URLs with malicious spamming code (and who knows what else) is something seen very often in these forums.

The website calls itself PDF9FILLER (with additional 10 numbers.

The signs are this is an Adobe URL. However, the visible URL is not always enough to tell. What is the web site you signed on to? And why do you suspect you have been scammed?