In the card text of Doom-Tune GT19, it says that during the main phase you can syncro summon a monster using Doom-Tune G19 and one other monster on either side of the field. The game does not allow you to select your opponents monster for this effect.
Bug reproduction steps
Set Doom-Tune face down (easiest to do by using the prediction princess engine) then flip it face up, triggering its effect (During your turn). It will prompt you to choose a level to set Doom-Tunes level to, but after that you cannot use the syncro summon effect even if you have the correct monster to summon and the levels required are on field.
- Screenshot OR error code
In the screenshot, the intended target is “Leo, The keeper of the sacred tree”. It is a level 10 monster and requires one tuner and 1+non-tuner. This sc was not taken inside a chain, and the was no promp for one to start after the level was selected.
What OS are you using