Unfortunately there is no solution.
Best thing one can do is send a bug report to Larian and hope they finally acknowledge this issue, as it's been ignored since launch despite being continuously reported by so many for almost a year now.
Until it gets fixed or 'if it even gets fixed'; the only temporary workaround is to manually make it use the proper resolution each time the game is launched or use the VULKAN API instead as it doesn't have this issue.
