Repeat Connection Drops

When using WiFi my connection drops for about 30-40 seconds and then reconnects this happens about every 30 minutes.  When plugged directly to the modem there is no loss of connection. My modem is a cox modem, my router is new.  I have the highest speed available.  I teach online and the multiple disconnecting is causing me to evaluate other providers.  

Has anyone had any success in solving this issue?