As soon as I found a glow squid in survival, I wanted to make a glow sign. I placed the sign, wrote text, and tapped it with the glow inc sac. Nothing. I tap and hold with the glow in sac. The sign breaks. I throw the inc sac at the sign. Nothing. I even got my friend on a Ps4 (they have two seperate buttons for "use" and "destroy") to join the world, gave him the inc sacs, and he tried tapping on the sign to make it glow. Still nothing.
Is this a bug, or are glow signs intentionally left out of Bedrock edition? If not, how am I supposed to make the text glow?

(I'm sure i didn't just "not notice" the glow. The glow inc sac was never used up.)