Switch Catch a Scorpion Carp Quest (Desert Festival)

[Lisastardew]

So this is the second year in a row I've attended the desert festival, and same as last year, the second fishing quest is to catch a scorpion carp. Last year I couldn't catch one all day, so I was determined this time. Well, I've reset the day twice and done nothing but fish and never saw a single one. They are definitely still there on normal days, seemingly at their normal spawn rate of about 15% - they just don't exist on the second day of the festival or while the quest is active, not sure which.

Anyone else notice this? (Or, conversely, been able to complete this quest without problems?)