https://www.ikea.co.jp/ redirects to https://www.ikea.com/jp/ja/ , which is why the Japan site doesn't have the same problem.
Bug 1987357 Comment 17 Edit History
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https://www.ikea.co.jp/ redirects to https://www.ikea.com/jp/ja/ , which is why the Japan site doesn't have the same problem as .tw.
https://www.ikea.co.jp/ redirects to https://www.ikea.com/jp/ja/ , which is why the Japan site doesn't have the same problem as .tw. (9D 5D is a two-byte character also in Shift_JIS.)