Microwave resets after 3 secs

Panasonic Microwave model NN-CS596A resets in 3 secs when on Microwave mode.

However, convection heating alone works fine. The units count-down timer works fine.

Checked and found all the switches and relays to the High Tension Unit are working fine.

About 8 months ago I changed a new High Tension unit and the Magnetron.

Now, unable to determine if it’s a Digital Programmable Unit or High Tension Unit error.

Magnetron ohms reading are good.

Any pointers appreciated.