Can't flash firmware

[Marth51]

Well, I flashed a SANDERS 28.49 Firmware running a XT1800 G5s Plus, but idk I have issues like wifi not working (can't activate it), calls have no sound, some bluetooth devices won't work and i'm trying to flash a newer version of sanders (28.65) trough fastboot, but I get preflash validation failed, security version downgrade, etc, and I cannot even install any custom rom trough TWRP because error 7 (even with the updater-script modified)

Getvar:
(bootloader) version: 0.5
(bootloader) version-bootloader: moto-msm8953-C2.12
(bootloader) product: sanders
(bootloader) board: sanders
(bootloader) secure: yes
(bootloader) hwrev: P4
(bootloader) radio: 3
(bootloader) storage-type: emmc
(bootloader) emmc: 32GB SAMSUNG RX1BMB RV=08 PV=07 FV=0000000000000007
(bootloader) ram: 3GB SAMSUNG LP3 DIE=6Gb M5=01 M6=05 M7=00 M8=7B
(bootloader) cpu: MSM8953
(bootloader) serialno: ZY322G2DJF
(bootloader) cid: 0x0032
(bootloader) channelid: 0x1a
(bootloader) uid: A0A21E0800000000000000000000
(bootloader) securestate: flashing_unlocked
(bootloader) iswarrantyvoid: yes
(bootloader) max-download-size: 534773760
(bootloader) reason: Volume down key pressed
(bootloader) imei:
(bootloader) meid:
(bootloader) date: 02-14-2018
(bootloader) sku: XT1800
(bootloader) carrier_sku:
(bootloader) battid:
(bootloader) iccid:
(bootloader) cust_md5:
(bootloader) max-sparse-size: 268435456
(bootloader) current-time: "Sat Jan 3 5:41:14 UTC 1970"
(bootloader) ro.build.fingerprint[0]: motorola/sanders_retail_n/sanders_
(bootloader) ro.build.fingerprint[1]: n:8.1.0/OPS28.49-2/202c:user/relea
(bootloader) ro.build.fingerprint[2]: se-keys
(bootloader) poweroffalarm: 0
(bootloader) ro.build.version.full[0]: Blur_Version.28.11.2.sanders_reta
(bootloader) ro.build.version.full[1]: il_n.retail.en.US
(bootloader) ro.build.version.qcom: LA.UM.6.6.r1-08500-89xx.0
(bootloader) version-baseband: M8953_41.50.07.79.01R SANDERS_LATAM_CUST
(bootloader) kernel.version[0]: Linux version 3.18.71-perf-g099018b (hud
(bootloader) kernel.version[1]: soncm@ilclbld31) (gcc version 4.9.x 2015
(bootloader) kernel.version[2]: 0123 (prerelease) (GCC) ) #1 SMP PREEMPT
(bootloader) kernel.version[3]: Wed Feb 6 03:43:34 CST 2019
(bootloader) sbl1.git: git=MBM-NG-VC2.12-0-g698fb2f
(bootloader) rpm.git: git=92e5e21-dirty
(bootloader) tz.git: git=e619e20
(bootloader) devcfg.git: git=e619e20
(bootloader) keymaster.git: git=e619e20
(bootloader) cmnlib.git: git=e619e20
(bootloader) cmnlib64.git: git=e619e20
(bootloader) prov.git: git=e619e20
(bootloader) aboot.git: git=MBM-NG-VC2.12-0-g07ff23c
(bootloader) frp-state: no protection (0)
(bootloader) ro.carrier: retar
(bootloader) current-slot:
(bootloader) slot-suffixes: _a
(bootloader) slot-count: 1
(bootloader) slot-successful:_a: INVALID
(bootloader) slot-successful:_b: INVALID
(bootloader) slot-bootable:_a: INVALID
(bootloader) slot-bootable:_b: INVALID
(bootloader) slot-retry-count:_a: unknown
(bootloader) slot-retry-count:_b: unknown