This is more common than you might expect, and there are a few likely causes:

Cold or bridged solder joints. Inspect every joint under magnification. A good joint is smooth and shiny, and wets the pad fully. A cold joint looks dull or cracked. A solder bridge is a small blob connecting two adjacent pads. Both cause intermittent or hard faults.

Wrong component orientation. Diodes, electrolytic capacitors, transistors, and ICs are all polarity-sensitive. Double-check that each one is oriented correctly against your schematic.

Missed connections. On a solderable breadboard (SB830/SB400), the track layout is the same as your solderless board, so direct transfer is straightforward. On StripBoard or PadBoard, it's easy to miss a wire or solder a connection in the wrong location.

Power and ground continuity. Verify that power and ground reach every part of the circuit. A quick check with a multimeter in continuity mode before powering up will catch most wiring errors.

Parasitic effects that the breadboard was hiding. Occasionally a solderless breadboard circuit works despite intermittent contacts, then on a soldered board, these problems appear. Check that all IC inputs are tied to a defined logic level.