Well, the feather in my cap is ruffled and deformed....
My last suggestion probably falls flat. Instead, try this:
The timer is basically a flip-flop, two op amps, a resistor network, an inverter buffer, and a discharge transistor. The resistor network provides two threshold points: 1/3vcc and 2/3vcc. The "Threshold" input is connected to the op-amp that references the 2/3 mark. When the voltage climbs higher than that, it flips the flip-flop and activates the discharge transistor, which sinks that DIS pin to ground. At the same time it causes the output to go to VCC. When the voltage on the "Trigger" input drops below 1/3vcc, it flips the flip-flop which turns off the discharge and pulls output to GND.
So for astable operation we set up an external resistor and capacitor network around those principals. As the capacitor charges, it goes through R1 and R2 to charge C1. When the voltage at C1 reaches 2/3vcc, DIS pulls it towards 0 and it discharges through R2 only, until it reaches 1/3vcc and then restarts the cycle. So total charge time once established is 1/3(R1+R2)C seconds, while discharge time is 1/3R2C.
So this circuit's intent is to pull the trigger and threshold to 0 while not paused. This keeps the output pulled towards ground, which pulls power through the LED from +5. So, always on. Then when you switch to pause mode, it allows the 555 to work in astable mode since it's basically disconnected from the pull-down.
So as Bullwinkle says, THIS time for sure!
PS: This setup also removes the need for a diode.
PPS: It's actually not that odd that the 555 sorta works without a ground. I remember a youtube video from Dave of EEBlog a while back where he demonstrated that a microcontroller can still do a blinky LED thing without all of its proper power and grounds. It was a bit weaker, and most likely it won't be reliable, but it was at least functional. Note that he was *not* recommending such a setup, but was pointing out that it could lure you into a false sense of security just because it "works".
Edited by ChildOfCv, Mon Feb 11, 2019 11:12 PM.