I linked to three earlier threads there, the way I've always done with the "link" button. One for example was "Payroll employment rises by 161,000 in October; unemployment rate changes little (4.9%)", at http://www.democraticunderground.com/10141615960.
This morning it was fine (work Dell laptop, Windows 7, MSIE-something). Tonight, the | symbol had been stripped, and the links could not be seen. They were still there, but with the | symbol gone, the software did not see the characters as a linked thread.
I put the symbols back in the three links, and they appear again. This was at my public library (Dell desktop, Windows 10, MSIE-something).