Update Jammer’s mandatory trigger effect to give a monster two attacks can be declined to be activated, activated after an optional trigger effect and activated on the first turn(when there is no battle phase)
Bug reproduction steps
Link using Update Jammer.
Screenshot OR error code
Update Jammer should be a fixed (Mandatory effects like Madolche S/T’s as well as Abyssmegalo’s battle phase effect work properly, so it appears to be isolated to Update Jammer )
Were you playing with TCG or OCG rules? For the latter, please refer to Update Jammer – Yu-Gi-Oh! TCG Product Errors (yugioh-diffs.github.io).
I first noticed this in TCG ranked, but I have only replicated it in test room(which I’m not sure what rules it follows)
I put up a fix for this, but because of the regional difference, you will have to wait for a database entry to be added for it to properly play Update Jammer with TCG text.