This happens because clones kind of “remember” the stage they were taken from.
If a clone comes from a plant that was already mature or in flower, it can start showing pistils even under a veg light schedule. The hormones haven’t reset yet, especially if the clone is still rooting or a bit stressed.
It’s pretty common when:
the cutting was taken from a flowering plant
the clone is still building roots
the genetics are a bit sensitive
Most of the time it’s nothing to worry about. Once the clone is well rooted and happy, it’ll usually stop flowering and go back to normal veg growth after a couple of weeks. You’ll see the new leaves return to normal shape.
Only a problem if it keeps flowering long-term — or if it’s an auto (autos won’t re-veg).
In short: normal behavior, just give it time and steady conditions 🌱