SonarLint is not computing duplicated code in projects. That’s why rule common-xxx:DuplicatedBlocks is not reported by SonarLint, whatever the language. Computing duplications could be quite expensive on big projects, and requires to analyze the same scope than SonarQube to report the same results. So for now we have decided to focus on static code quality rules.
I have not tested with SonarPHP 2.15 that is more than one year old, so I suggest you try in standalone mode (comment out the connected mode configuration to use the default embedded SonarPHP analyzer) or ask your SonarQube administrator to update the SonarPHP plugin.