Shield Exprience Upgrade 5.2 stuck/loops

hi guys/girls

android TV shield 2015 16 GB model.

well it is long been while… i gave up with 5.1 i want to more upgrades. but it was already old problem. i ignored it.
but i want to upgrade right now =/

i did installed via ADB
i remember i did type

fastboot flash system system.img
fastboot flash vendor vendor.img
fastboot -w
fastboot flash recovery recovery.img
fastboot reboot

any someone have idea how to fix those?

thx you

Any someone know how to fix? and please thank you a lot.