My printer is also an Ender 3 Pro. There are really just three possibilities here.
The first one goes with my Rule #11 "Always go back to the last thing you did." and in this case it's the extruder arm. You didn't mention whether it was the stock plastic arm or if you had an aluminum arm. The stock plastic arms ALL break. There have been instances where they were broken when first taken out of the box. So take it off and look at the underside around the pivot hole (it should be a brass insert). Get it under a good light and look for cracks around the insert. A magnifying glass would be helpful.
The second thing is a partial clog at the bottom of the bowden tube where it is supposed to seal against the back end of the nozzle. You need to warm up the hot end and pull the filament out, then pull the cover off the hot end and remove the nozzle. From the top, take out the bowden tube. Sometimes they are stuck in there pretty good and it's easier to pull the other end out of the extruder fitting and slide the hot end fitting off that way.
A properly sized piece of wire (maybe a straightened out coathanger) can be shoved down all the way through the hot end. If it pushes out a plug of plastic you have your culprit. In a pinch you can use a 300mm long piece of filament (but ya gotta go fast because the hot end will start melting it immediately). I'm sure CHEP has a YouTube video on the proper way to trim the bowden tube and re-assemble everything. Trimming it with a single edged razor is the best way. The cut must be as close to 90° as you can get it. If you haven't done so - buy some Capricorn tubing to replace the stock bowden tube. It doesn't break down as fast. Remember that the bowden tube is a consumable and they don't last forever.
The third thing is really a pain in the wallet. If the E-stepper chip on the mainboard died then it just isn't pushing as much plastic as the gcode is asking for. If you re-calibrate your E-steps and they turn out around 250 or 300 then the chip has fried. Your E-steps should be somewhere in the range of 90 to 110 (mine are at 100). This is not repairable and you would need to replace the mainboard.
So there you are. Don't feel bad or overwhelmed. My printer went through all three of those.
@gr5 used the term "Under-Extrusion" correctly but "Erraticallyk"...I don't know. I thought it had a couple more rrrr's in it.
It's a little hard to tell from the photos (white filament would be better) but I think it is underextruding. Erraticallyk and by a LOT.
1) What speed are you printing at?
2) Please post your project file (do menu "file" "save project")
3) Please post a picture of your feeder with the repaired handle. Maybe you assembled it wrong or it broke?
There are quite a few Ender 3 people here including the very helpful @GregValiant. So answer 1,2,3 and he may has some great advice.
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