Solution
You need to check RTF syntax for a hyperlink that set in RTF file. For RTF file, the syntax for hyperlink is different compare to other type of files.
You can edit the hyperlink in the file by referring to this:
{\field{\*\fldinst HYPERLINK "URL"}{\fldrslt Text to display}}
For example, you want to have NI hyperlink, you can edit the syntax for NI hyperlink in RTF file as follow:
{\field{\*\fldinst HYPERLINK "https://www.ni.com/en-us.html"}{\fldrslt NI}}