I think its because razor consumes the <script part and only passes the rest > ... <script to html.
It should use a lookahead instead of a capture.

heres some bug reports:

• https://github.com/dotnet/razor/issues/12011
• https://github.com/dotnet/razor/issues/11820
• https://github.com/dotnet/razor/issues/10049
• https://github.com/dotnet/razor/issues/5715
• https://github.com/dotnet/razor/issues/4427