Hey

It's not a bug.

Different areas of Player Verses content has its own merit of summoning.

The tab allows you to select 3 Summons, meaning it's wise to alter the summons for each instance.

For example. Summon 1 for Ranked Battle, Summon 2 for PvP and Summon 3 for Other

unfortunately, it's not a bug.

Hopefully, that helps clear up a bit!