@SammyG , This is strictly a guess, but maybe your PowerConfig Settings aren’t actually being used during the 10 sec delay since that’s the next operation after the changes are made and still within the Startup() Macro ?
IIRC, the charge light only burns when the charge rate is ~50 mA or more ( from memory, might be incorrect).
The 1Hz blinking “could” simply be the DPM working correctly, but just at the threshold for that particular panel and light intensity to maintain the panel at 5.08V.
I’ve seen this situation several times on my Solar Panel Test Stand, where increasing the intensity immediately stopped the 1Hz blinking pattern. The Boron was always re-charging, it’s just the LED fools ya.
You might want to try Particle’s INA219 and OLED feather (here’s a thread) for bench testing.
It removes the guesswork and tells you what’s actually being stored or sourced (to/from) the Li-Po at any operating condition. I don’t have the 0.6W voltaic to test, but my guess is 70’ish mA “net” in full sun at 5V .
If you add a POT, you can perform a curve trace for your specific panel and know what it produces at 5.08V at various light intensities. The INA219 feather is an inexpensive tool with a lot of potential uses on the test bench if you don’t have the benefit of Lab Grade Equipment.