titleregexp is not doing what it has always been

Created by: ukcb

Hello, I have defined:

titleregexp=^xxxxxx/2016-[0-9]{3}$

Extension:DynamicPageList (DPL), version 3.0.10: Warning: Skipping bad option '^xxxxxx/2016-[0-9]{3}$' for parameter 'titleregexp'.

With brackets it works fine!

titleregexp=(^xxxxxx/2016-[0-9]{3}$)

Is this a new mode or a bug? My wiki has many of these instructions, I would have to adjust everything. :-(

mediawiki 1.27.1