Is there a word to describe the situation when a system that you created yourself surprises the author?

The circumstances you describe are to some extent:

Frankensteinian = anything that becomes dangerous to its creator

Collins Dictionary

Other definitions go beyond the inconvenience you describe to more perilous things:

Frankensteinian = a person who creates a monster or a destructive agency that cannot be controlled or that brings about the creator's ruin

Dictionary.com

Nevertheless, the word has the necessary feeling of something created that then gets out of control for its creator.

As is widely known, the word derives from Mary Shelley's novel Frankenstein

[Gutenberg]{https://www.gutenberg.org/files/84/84-h/84-h.htm)