This WP article and parent’s video are both fun, I enjoyed this momentary rabbit hole. The video above claims there’s a difference between a Mondegreens and Eggcorns, which is that Eggcorns are mis-heard phrases that have the same meaning as the original, while Mondegreens change the meaning. Plus the video has a clip of the ‘Mondegreen’ song sung with a strong Scottish accent - check it out if you didn’t make it that far!
Deep seated.
https://www.merriam-webster.com/grammar/deep-seated-deep-see...