Playback becomes choppy after long duty cycle-- unplugging USB at board fixes it, but why?

[unfussyorg]

Maybe this belongs in a more general Arduino forum, but thought I'd try here first. The code is based on the examples I saw here.

I've got my ESP32/1053 installed in an old radio. The Arduino circuit is powered by an Apple 5V cube charger, which is tied into mains before the radio's power switch. This means the Arduino section is always powered on (if the radio is plugged in), and the power switch just controls the original radio's amplifier circuit.

This has been working great, but once or twice a week I'll turn the radio on in the morning and the sound will be slow and choppy (the Arduino will have been running all night). Oddly, a single station out of twelve (95B Auckland) is never affected. Nothing special about it that I can see:

Immune to bug:

// 7 - 94FM "95B" Auckland
char *host7 = "streams.95bfm.com";
char *path7 = "/stream128";
int httpPort7 = 80;
char *httpver7 = "HTTP/1.1";

Not immune:

// 3 - 90FM KEXP
char *host3 = "kexp-mp3-128.streamguys1.com";
char *path3 = "/kexp128.mp3";
int httpPort3 = 80;
char *httpver3 = "HTTP/1.1";

What I've tried

• Added an external reset switch for the ESP32, maybe the code needs a fresh start from time to time. On reset, the choppy audio persists.
• Unplugged the radio power cord from the wall, perhaps everything needed a power cycle. No difference on restart. Also tried waiting 10min for the magic smoke to settle before plugging back in.

What works

• Unplugging the USB cable from the ESP's port, then plugging it right back in. Immediately on reboot all stations are clear. Obviously this isn't a good final solution because once the radio is assembled, I don't have access to do this.

Questions

1. Does the sound of the audio point to a specific fault?
2. Is the 24/7 duty cycle a factor, or just making the bug surface more often?
3. Am I discharging something by touching the ESP to unplug the USB?
4. Where I should start to troubleshoot this?

choppySound.mp4