If the repeater can detect another DHCP server, then it won’t start up it’s own DHCP server. Detection is one by requesting a DHCP lease for itself. However, the DHCP client used in TP-Link products hasn’t been updated since 2014 and contains known compatibility problems with DHCP servers; especially related to failing to renew existing DHCP leases.

If you know you already have a DHCP server on your network (e.g. in your router/gateway) then you should disable all other DHCP servers. Multiple DHCP announcements on the same network can lead to a lot of problems with multiple devices announcing themselves as the default route.