When merging records in Raiser's Edge Patch 8 which has new consent functionality, the consent information is not merged to the destination record.
This is resolved in Raiser's Edge 7.96 patch 11, released in May - June 2018, and applied to databases in Blackbaud Hosting Services. If your database is locally installed, download and install the latest patch, if applicable. For more information on patch 11, see What is in patch 11 for The Raiser's Edge 7.96?
Important The process of merging constituent records also merges their Solicit Codes therefore please note that it is important that you review Solicit Codes when the constituent merge is complete, as it could result in conflicting Solicit Codes. Should this occur, you should review the Consent History to identify which are the latest / valid Solicit Codes for the constituent and amend if necessary.