It has nothing to do with the container, but is just the result of your plant being a little confused about "all this growing thing" it is meant to do. It seems the newest leaves are growing fine, so your plant is now on the path to flowering and the funny leaves are nothing to worry about. If it continues then your plant might be a bit weird and deciding on its future should be left for another week or two. It may be worth planting a replacement in case this plant continues being weird and does not grow properly, which would indicate a "genetic flaw" with this particular seedling.
Hope this helps,..........
Organoman.