Contact Fusion is treated as a real fusion summon, even though they don’t say that they are treated as a fusion summon, so it should be treated as a special summon. This can wrongly trigger cards like Strength in Unity. Source 1: Yu-Gi-Oh! TCG Strategy Articles » Special Summons – Spotting the Different Kinds Source 2: In Duel Links, if you contact fuse Blue-Eyes Twin Burst Dragon, the character will call it a special summon instead of a fusion summon. Source 3: In Master Duel, if you contact fuse Blue-Eyes Twin Burst Dragon with Strength in Unity on the field, you won’t be able to activate Strength in Unity’s banish effect.
Bug reproduction steps
Activate Strength in unity, summon 2 Blue-Eyes White Dragons, use them to summon Blue-Eyes Twin Burst Dragon.
Screenshot OR error code
You shouldn’t have the option to activate Strength in Unity’s banish effect.
What OS are you using