I remember when 7x7 Go was apparently “solved” on December 2, 2015 as a draw with a komi of 9. See Solved game - Wikipedia and 7x7 Board at Sensei’s Library (last edited by @bugcat, incidentally).
The original article relaying this information is now hidden. But if memory serves, the authors conceded that it was a weak proof, involving trial and error among several professionals with the help of a computer engine. To this day, no better lines have been discovered. Yet 7x7 Go still awaits a mathematical proof.
This led to my special interest in 9x9, which also continues to this day.