Device is not recognized from Fastboot

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PC recognize the phone when it's powered on, but not from the Fastboot mode.Month ago I have rooted it with Magisk and today I have unrooted it (with Magisk App ‘Complete Uninstall’ option) and uninstall Magisk in order to flash LineageOS (this was maybe unnecessary step).Is it possible that my phone is unrecognizible because patched boot image?