If you are one of them, you’ve got the option to refer to this post.
This post fromMiniToolprovides some useful and feasible methods for you to fix the issue.
What would you like to do?.

Then, there are two options for you Stop it or Wait.
Now, lets see how to fix the a web page is slowing down your surfing app Firefox issue.
Now, follow the steps below to fix the a web page is slowing down your surfing app issue.

Step 1:OpenDevice Manager.
Next, expandDisplay adaptersand right-click your graphics card to selectUpdate driver.
Step 2:SelectSearch automatically for updated driver softwareand let it finish the process.
If the above steps helped fix the issue, you should exit and restart the PC.
If not, then continue.
Step 3:Again right-click your graphics card to selectUpdate Driver.
This time on the next screen selectBrowse my computer for driver software.
Step 4:Now selectLet me pick from a list of available drivers on my computerand clickNext.
Step 5:Finally,opt for latest driverfrom the list and clickNext.
Let the above process finish and reset your PC.
Then you could see if you have fixed the a web page is slowing down your surfing app issue.
If not, continue with the next step.
Solution 2: Disable Adobe Flash Protected Mode
Adobe flash protected mode was launched to protect Firefox.
It is a security feature that makes it difficult for attackers to attack your gear.
However, it can cause hangs, errors, or plugin crashes.
Step 1:Open Firefox and go toAdd-ons.
Then, navigate toPlugins.
Step 2:Go toShockwave Flash>3 dots on right corner>Select Never Activate.
Step 3:Then, clickNever Activate.
Now, check to see if the issue has been fixed.
If not, try the next solution.
Step 2:Scroll down to find theCookies and Site Datasection, and click theManage Databutton.
Step 3:go for the target site, clickRemove Selected, and click theSave Changesbutton.
ClickYesin the pop-up window to scrub the cache for this site.
Now, check to see if the a web page is slowing your surfing app issue has been fixed.
Step 1:Open Firefox and typeabout:configin the address bar.
Step 3:Then, typeprocessHangin thesearchbar.
There will be two options.
Right-click each and clickToggleto set both toFalse.
Now, the issue should be fixed.
If you have come across the same error, try these solutions.