how to get Link Register when it has 0xFFFFFFF9 in ISR

I have here invalid value to LR when any normal ISR was happened. every Isr get the same behavior.

how can I know LR Value in this case to get the previous code line which was executed before this interrupt.

and why in call stack "exception Frame" appeared in a normal isr ? and where the previous call stack view before isr in call stack window?

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