Mining certain blocks causes them to drop the wrong tiles.
stone drops stone instead of cobblestone
Diamond, redstone and lapis ores drop their respective ore blocks instead of the actual item
Glowstone drops glowstone blocks instead of glowstone dust.
This screen recording shows it pretty well.
Thank you for your report!
However, this issue has been closed as Working as Intended.
As you are using a Silk Touch tools, the drops are expected to drop as you've described:
[media]https://minecraft.gamepedia.com/Silk_Touch
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