Based on the info you provided there are two problems.
The lower oven need a new relay board (assuming that you took off one wire from the element when measured the continuity) Part number: 318022001
For the upper oven you should check if the thermal resettable switch is open.It's on the back of the oven ,but you should be able to check it from the upper relay board .
Check continuity from Yell/Blue wire BA to one of the brown wires from the DLB relay. No continuity - remove oven and reset the switch.
If the switch is OK - replace the upper relay board Part number: 318022002
The thermal switch Part number: 318004900
Here are the breakdown diagrams and Control Panel parts for Frigidaire GLEB27T8CSA - AppliancePartsPros.com
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