I've compared it with search urls that work and they either don't have the "ds_c=" or they do have it and it doesn't have anything between the "=" and the "&" (e.g. ds_c=&). Here is an example of a working url:
Here are the facts so far:
-Only occurs on mobile
-Only occurs on certain browsers (seems to be only Chrome + Safari)
-Seems to be impacting responsive search ads
-The offending url's all had [*Campaign*] following "ds_c="
Anyone had this issue themselves or have an idea of how to fix this/locate the issue?