You can try following patch to enable location search:
https://patch-diff.githubusercontent.com/raw/sharetribe/sharetribe/pull/3256.patch
Apply it to your code:
wget https://patch-diff.githubusercontent.com/raw/sharetribe/sharetribe/pull/3256.patch
patch -p1 <3256.patch
Then rebuild sphinx index:
rake ts:rebuild
Restart your server and delayed jobs worker.
In admin settings then change search mode to “keyword and location”.