thats the excat first thing i tried. The scientist won't give me.
and I did a deep check, heres what i found:
After I unchecked the received castform box, and I saved the event flag, then export the whole save file, the received castform boxed will turn to checked status again.
OK I figured it out. I used a 2018 version of PKHEX to unchecked the event flag, and saved it, and then used the most updated verstion to unchecked and save it again, it works.
By the way the old version of at least event flag part is much better than the newest one. The older only shows events like "Received A/B/C/D/..." OR "A/B/C/... captured", instead of the new one have so many disturbing boxes(i.e. the don't spwan check)
left old, right new