There is a known link issue that only occurs in Gmail. The issue is not isolated to Zulu eDM, it is widely known. We have identified some possible solutions and will try and resolve the matter during the year.
Links work fine in all email clients except the odd link with Gmail.
The issue is their handling of the URLEncoded Characters.
If you are able to reduce links to be shorter in length this can help.
Using the Google Short Link or Bit Links does not work.