Access Point SSID changes to match SSID of main router
So I have a Tp-link Archer C1200 that I use as my main router. Recently I purchased a new Tp-link Archer C80 which I have connected via ethernet to the C1200 and the C80 is set to access point mode. Both devices are broadcasting both 5 and 2.4 networks for a total of 4 SSIDs, all of which have been given different names. Now here's the issue. After a few days of setting the C80 as an access point, the 5Ghz SSID of C80 changes automatically to match the 2.4Ghz SSID of my main router C1200. A restart fixes the issue but it happens again after a few days. I've already tried resetting. I tired connecting to the C80 on its LAN port as well as WAN port and either way the issue persists.
Anyone got any idea as to what's causing this issue?