Flush is quite stressful for the plant.
when it's on the tips like that all around before anything else, it's likely a K-deficiency. If in soil it depends on how much nutes you leached out of the substrate.
always try to avoid flushing. if pH is off, pH-adjust next fertlized water irrgation and get some extra runoff or if not a fertilized irrigaiton start with a little extra runoff before going all out with a large flush.
If pH was way off it could have locked it out if too far below 5,5. oh fuck i wrote all of this and i'm gonna get a banned message. will copy and paste to DM