For those sort of "mother's maiden name" type questions, I generally use a fake but plausible name. Probably not as secure as a random string (especially as the

For those sort of "mother's maiden name" type questions, I generally use a fake but plausible name. Probably not as secure as a random string (especially as the name is reused across a few services), but makes it near impossible to research, and avoids a random string not being accepted/treated as an error/truncated like your example etc.