gravity fed well pressure issues

We moved onto a new property last November, and it has an interesting well situation. The well is a dug well, granite slab lined. It's actually located off the property, across the road from us and roughly 2,500+ feet into the woods. It's a decent elevation gain, so the entire thing is gravity fed. A black poly tube comes from our property/house, and runs underground, under the road, up through the woods and into the well about 2-4 feet above the bottom of the well. There it terminates into an elbow, and then the end of the tube is covered with a screen which is held on by a band clamp. (I'm currently looking into ways to improve this setup, but right now it's dead simple and has been there like this for a few decades after they swapped out rigid lead pipe due to regulations).

Now that you've got a rough idea of the well and piping set up, here's the brief history of the issue. We run a small herd of goats (10) and chickens (50), and pigs (4), which use a decent amount of water. We also have used it to sparingly drip irrigate our 1 acre of vegetables, as well as washing those vegetables 3-4 times a day during the summer. Additionally, this well is supplying water for the house, which at any given time has 4-6 adults living in it doing dishes, laundry, etc. We're fairly conservative in our water usage, but obviously we're using more than the average homeowner. Now, historically this well has never been known to run dry, and has been used by locals with livestock when their wells ran dry or lines froze in winter. I don't think we have a supply issue going on, and have been checking the well when we have had issues.

The issues began about a month and a half ago, when water pressure suddenly dropped significantly and then virtually became nonexistent over a 3-4 day span. The well was half-full, and water about 3-4 feet above the supply line during this time. We eventually had more rain, and over a few days the pressure came back. Since then, we have had two more of these episodes, resulting in similar times with almost no water whatsoever. We're currently involved in one, and despite a 6" rain event yesterday, we have not fully recovered water pressure, even without doing any watering, washing, flushing, etc. The interesting thing is today, and maybe it's due to all the rain we just had, but from the well toward the house, there is standing/running water above ground. On the ground above the well, this isn't an issue.

I have a few calls out to local well drilling companies but no leads yet and figured I could try online also to get some ideas on the issue, as well as hoping to find any tips on looking for potential leaks (other than digging the entire line from well to house). I've attached two photos, one showing the well a on Tuesday when the water level had dropped below the hose line, and today after our recent rain event.

Thanks in advance for any help!

I can't interpret the photo very well, but it looks like that elbow piece of the pipe is at higher elevation than where the pipe exits the spring-box. If you reworked that could you take water out from lower in the spring-box?

I'm wondering if the pipe is not downhill all the way to it's outlet? That could allow an air bubble to form somewhere along the line which might slow or stop the flow of water. A solution to that issue would be to pull a vacuum at the inlet, or force high pressure water into the outlet.

Air lock was what I was thinking too.

https://en.wikipedia.org/wiki/Air_lock