Hello
I hope you have managed to solve your problem. I would like to post my solution in case i can help someone. I had the exact same issue. Ipad 4 4g version with snapped data module flex cable. I ordered the replacement flex from ebay and aliexpress but due to covid-19 lock down, they have not been delivered to me after 3 months. So i fixed it the old fashioned way. The ipad works,the bootlooping has stopped and also data connection (2g-3g-4g)works.
I am sorry for the “glowing” but i took the picture after i applied loca glue for isolation.
I
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