[Angular2] how to solve the problem with ERROR RangeError: Invalid language tag: en-US,?

through untold hardships, I finally found this mistake. As a result, I was a little confused. What on earth is this mistake?

the following figure is shown:

and this bug is not available on all mobile phones. It seems that Android phones around 6. 0 will appear.

Boss, please answer ~

checked Baidu and Google, only some problems on Google are similar to mine, but I don"t quite understand what I said above.
https://github.com/moment/lux.
https://stackoverflow.com/que.
https://stackoverflow.com/que.

the above three are found, similar situations.

Angular2 node.js html5

Mar.21,2021

well, no one replied, so I wrote the answer myself. After reading
on Google for a long time, I probably know that there is something wrong with the compilation of pipeline data, and maybe the lower version of Android won't support it.
so, there is no time to dig deep into the deep layer, so I'll just solve the surface one and remove the pipe.

write a data conversion method and call it to display the desired format. In this way, the mistake will not be reported.

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