Hello! I'm trying to figure out what is going on with my 2002 Ranger xlt 4.0L. There are no check engine lights

When I crank it up it jumps to a little over 2200rpm for about 10 seconds before slowly and jumpily falling down to about 1200. After the car warms up after about five minutes it will finally lower to about 750 but it idles a little rough, shaking the truck. Pressing the gas pedal for a second then releasing causes the RPM's to jump up over 2000 for around five seconds before slowly and jumpily lowering once more.

It was worse than this at first because it broke down with me on the side of the road (wouldn't accelerate past 1k rpm, eventually sputtered and died, all after a sharp turn onto the highway). After we got it home, we found a loose vacuum hose and reattached it and it ran a little better with the above problems. I'm wondering if we have a vacuum leak somewhere. I checked all the hoses and all are now seated nicely though I found one that I'm concerned about and I'll post a picture. It's an elbow hose that is squishy in the middle and when the truck is running it collapses inward. Do yall think this elbow is the reason for the above problems? I didn't see any cracks on any hoses, didn't hear any whistling sounds indicating a leak, the mass air flow sensor was replaced with no effect, and the iac was cleaned thoroughly with no effect. New fuel pump too after the old one died about a month before this. The only check engine light that popped up happened when it broke down and stranded me on the side of the road.

Thanks! At the very least I'm hoping people can learn from the image I posted to know what the hoses can be like

Hose collapse while running. No cracks or holes noticed