Anniversary Festival. Convokenz Rushman Quest

I took a quest from Convokenz Rushman within Anniversary Festival and arrived at Lake of Magic Mist. I didn't find any frogs.

I read https://wiki.chroniclesofarcadia.com/festivals/anniversary, it didn't help

Please explain in detail how to complete the Convokenz Rushman quest.

I used the right time. I drove around the perimeter of the lake, swam it repeatedly, I didn't find any frogs. Today I did the same thing, in addition, I looked at the island in the middle of the lake. The frogs were there.