I recently upgraded from v2022 to v2026 and see a problem with the horizontal legend positioning when I set it to Top or Bottom.
In 2022 (bottom image) the legend is centered under the chart. In 2026 (top image) the legend is under the chart, but at some random horizontal position.
In TeeChart v2022.38 we fixed #2425.
The Legend’s TopPos wasn’t being used when the Legend is aligned to Top/Bottom.
But, that property has a default of 5, so that fix moved existing Top/Bottom aligned Legends a 5% to the Right.
Try changing that TopPos property to zero: