This is mainly red-channel overexposure, possibly made worse by camera shake. In dark scenes, the camera often exposes for the overall darkness, so bright red signs blow out before the rest of the image. Instead of going white, the red channel clips and detail disappears into a solid red patch.

To reduce it while shooting:

• Use less exposure: faster shutter speed, smaller aperture, or lower ISO.
• Stabilize the camera with a tripod or other support, since a slow shutter can blur lights into blobs.
• Check the histogram if your camera shows RGB channels; that can reveal a clipped red channel even when the full image doesn’t look totally overexposed.
• Consider multiple exposures and blend them later if you want both bright signs and dark surroundings.

In post-processing:

• If you shot RAW, you may be able to recover some highlight detail by reducing exposure or using highlight recovery tools.
• If the red channel is badly clipped, recovery may be limited or impossible.

So the fix is mostly to protect highlights when shooting and use RAW when possible.