From what I can find online, Broadchurch is only available on PBS Masterpiece, or you can buy the episodes/seasons on Amazon Prime. I've watched all three seasons and think it's an outstanding series. Of course, I'm a big fan of David Tennant.
If you are watching it through PBS, then you need to contact them about the episodes available.
I do see that it's also available on The Roku Channel, and they are missing E02. However, that is probably as expected. When Roku licenses content to stream on TRC, they are not always given every episode and/or season to stream. That's out of Roku's control. The media owner makes the decision about which episodes they will permit to be streamed. So if you want to watch the missing episodes, you either need to subscribe to PBS or purchase them through Amazon, Vudu, or Apple TV. I found it available to purchase all three seasons on these services.
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