There can be many possible errors in Linksys performance and several reasons behind them. But, to fix the Linksys RE7000 sluggish working, you can take some of the common troubleshooting tips into account. The first one is to change and relocate the extender to another place by replacing the older one. As during the Linksys re7000 setup, you need to place the extender and router closer, you can move the extender after that. So, try moving the extender centrally to your place while keeping it within the router’s range. Further, you can make wired connections instead of wireless ones as the former ones are more reliable than the latter. If the extender is still working slowly you can check for its firmware's latest version and update that if there is a new version available. The updated version will surely bring the extender’s performance to its best state.