http://www.kcra.com/article/apple-text-bomb-can-crash-iphones-with-single-message/18237239 I wonder if it crashes only if you open the text message? You can preview it, so if you see the unicode, you can delete it before opening.
You don't have to open it, as seen in this YouTube video. https://www.youtube.com/watch?v=K73fw99Xb9s
iOS 11.2.6 just rolled out, i believe it patched this... https://www.forbes.com/sites/amitchowdhry/2018/02/19/ios-11-2-6-features/#6aafbc3b196c
We found 1 good reason to get the iOS 11.4 update – rogue message handling https://nakedsecurity.sophos.com/2018/05/31/we-found-1-good-reason-to-get-apples-ios-11-4-update/
PSA: New Character Bug in Messages Causing iOS Devices to Crash [Updated] April 23, 2020 https://www.macrumors.com/2020/04/23/ios-character-bug-device-crashes/
