Google Voice Gateway was previously stripping the + symbol but leaving the leading 1 on caller ID sent for US/Canada calls. This was non-standard behavior and has been fixed.
Incoming calls from US/Canada will show a ten-digit “national format” caller ID, with name (CNAM) if available.
Incoming calls from other locations will show a full-format caller ID including the + symbol and country code. Name information is not available for international calls.