どうしたわけか

Meanings

1

somehow; for some reason

usually written using kana alone

Used when the speaker does not know or does not specify the reason for a situation; often implies a sense of inexplicability.

どうしたわけか、今日きょうは電でん車しゃが空すいていた。
For some reason, the train was empty today.
どうしたわけか、彼かれは急きゅうに機き嫌げんが悪わるくなった。
Somehow, he suddenly got into a bad mood.

2

usually written using kana alone

Used to ask for a reason, similar to なぜ, but with a slightly more indirect or wondering tone.

彼かれが何なにも言いわずに出でて行いったのは、どうしたわけか。
Why did he leave without saying anything?
どうしたわけか、こんなに遅おそくまで連れん絡らくがないんだろう。
Why haven't they contacted me this late?