Glad to hear you got it sorted out.
While the more expensive breadboards and jumper kits are better, they are very far from perfect. So even if like me you buy excellent gear you will still have occasional puzzling intermittent connections.
My rules for least frustration with solderless breadboard prototyping:
- Always insert, half-remove, then re-insert the wires and components to clean the oxidation from both the wire/pins and the breadboard contacts
- Never make the circuit too large, prototype a small portion at a time. Once the circuit is designed and debugged I transfer it to a soldered breadboard before intermittent connections waste my time. (I have a hard limit 4" x 6" (100mm x 150mm) maximum for solderless breadboards at home and work)
- When you see intermittent operation, wiggle the wires and if that doesn’t help, insert, half-remove, then re-insert the wires again.
- When there’s a problem, confirm the electrical signals are correct at all connections with a multimeter.
Common pins in the alligator clips make great probes for this, they fit in the breadboard holes and easily probe component leads. If you have brass pins, either raw or nickel plated, you can solder up dedicated test leads - Most importantly always remember the connections will not be very reliable and will require troubleshooting of their own. It’s the price we pay for rapid prototype circuit construction.
FYI - the largest model I currently use is this one:
However, I don’t think it’s significantly better than this newer model at half the price: