Recover from Encryption unsuccessfull on zte blade apex2

I have an old Zte Blade Apex 2 with stock rom TIM-IT and stock recovery that can't start because of Encryption unsuccessfull error. It can boot in recovery with power + volume+ so as a first step I tried to wipe data and cache but the issue persists. The original rom is not available anywhere online, but some other provider's ROMs are available (movistar or Micro P UK), I tried to use one of those updates but the updater script will fail because of an assert on getprop("ro.build.product") which differs only by the network operator name. Clearly changing the updater script inside the zip causes "failed to verify whole-file signature" error. For this device there is a TWRP recovery available but currently it's not installed. I can run adb sideload (in recovery mode) and adb shell without root (from FTM mode, power + volume-), but trying adb restart bootloader will start the device normally with the encryption error. By booting power with volume+ and volume- together (that should be fastboot mode) the red led is on and the device won't be recognized by Windows 10 (USB device not recognized) while on ubuntu with lsusb I can see the usb device id (which is different from the one in FTM mode allowing adb commands) but the command fastboot devices won't show any device and also trying to manually provide the device id won't work. Any suggestion to recover this phone? UPDATE: I started the phone with power+both volume keys, lsusb gives ID 19D2:0112 ZTE WCDMA Technologies MSM QHUSB__BULK. while ./edl.py r recovery r.img keeps printing dots "Waiting for the device". In FTM mode ID 19D2:0500 ZTE WCDMA Technologies MSM Android I could run abd reboot edl but edl.py will return Library.sahara - couldn't find a loader for given hwid and pkhash :( Now lsusb gives 05c6:9008 Qualcomm, Inc. Gobi Wireless Modem (QDL mode) On windows it is recognized by MiFlash so it should be correctly in EDL mode, but how can I flash the TWRP recovery now?