[OnePlus 7T Pro 5G McLaren Guides, News etc.] :
i heard the same thing. probably going to ship to oneplus for reflash if you guys don't have any tricks. stuck in QCOM flash mode now :( no fastboot etc

---------- Post added at 07:13 PM ---------- Previous post was at 07:11 PM ----------

i did this. vendor.img appears to have the qualcomm code for support for 5g, and is the reason i bootlooped before trying to flash super.img etc. for anyone curious, the super.img didn't get to flash; that reboot that came before it stuck it in a qcom loop.

---------- Post added at 07:14 PM ---------- Previous post was at 07:13 PM ----------

if anyone cares for logs or can get me out of this qcom hell...

./flash-all.sh

Flashing partitions...

< waiting for any device >

Sending 'aop_a' (512 KB) OKAY [ 0.022s]

Writing 'aop_a' OKAY [ 0.005s]

Finished. Total time: 0.045s

Sending 'aop_b' (512 KB) OKAY [ 0.047s]

Writing 'aop_b' OKAY [ 0.004s]

Finished. Total time: 0.065s

Sending 'bluetooth_a' (1024 KB) OKAY [ 0.040s]

Writing 'bluetooth_a' OKAY [ 0.005s]

Finished. Total time: 0.062s

Sending 'bluetooth_b' (1024 KB) OKAY [ 0.041s]

Writing 'bluetooth_b' OKAY [ 0.006s]

Finished. Total time: 0.064s

Sending 'boot_a' (98304 KB) OKAY [ 2.756s]

Writing 'boot_a' OKAY [ 0.479s]

Finished. Total time: 3.252s

Sending 'boot_b' (98304 KB) OKAY [ 2.692s]

Writing 'boot_b' OKAY [ 0.461s]

Finished. Total time: 3.167s

Sending 'dsp_a' (65536 KB) OKAY [ 1.816s]

Writing 'dsp_a' OKAY [ 0.276s]

Finished. Total time: 2.105s

Sending 'dsp_b' (65536 KB) OKAY [ 1.773s]

Writing 'dsp_b' OKAY [ 0.265s]

Finished. Total time: 2.051s

Sending 'dtbo_a' (24576 KB) OKAY [ 0.686s]

Writing 'dtbo_a' OKAY [ 0.077s]

Finished. Total time: 0.779s

Sending 'dtbo_b' (24576 KB) OKAY [ 0.694s]

Writing 'dtbo_b' OKAY [ 0.100s]

Finished. Total time: 0.810s

Sending 'LOGO_a' (16384 KB) OKAY [ 0.456s]

Writing 'LOGO_a' OKAY [ 0.048s]

Finished. Total time: 0.518s

Sending 'LOGO_b' (16384 KB) OKAY [ 0.465s]

Writing 'LOGO_b' OKAY [ 0.081s]

Finished. Total time: 0.561s

Sending 'modem_a' (307200 KB) OKAY [ 8.292s]

Writing 'modem_a' OKAY [ 1.232s]

Finished. Total time: 9.539s

Sending 'modem_b' (307200 KB) OKAY [ 8.624s]

Writing 'modem_b' OKAY [ 1.209s]

Finished. Total time: 9.850s

Sending 'oem_stanvbk' (10240 KB) OKAY [ 0.276s]

Writing 'oem_stanvbk' OKAY [ 0.054s]

Finished. Total time: 0.346s

Sending 'qupfw_a' (80 KB) OKAY [ 0.015s]

Writing 'qupfw_a' OKAY [ 0.004s]

Finished. Total time: 0.033s

Sending 'qupfw_b' (80 KB) OKAY [ 0.010s]

Writing 'qupfw_b' OKAY [ 0.004s]

Finished. Total time: 0.028s

Sending 'storsec_a' (128 KB) OKAY [ 0.017s]

Writing 'storsec_a' OKAY [ 0.004s]

Finished. Total time: 0.035s

Sending 'storsec_b' (128 KB) OKAY [ 0.014s]

Writing 'storsec_b' OKAY [ 0.004s]

Finished. Total time: 0.031s

Sending 'multiimgoem_a' (32 KB) OKAY [ 0.009s]

Writing 'multiimgoem_a' OKAY [ 0.003s]

Finished. Total time: 0.028s

Sending 'multiimgoem_b' (32 KB) OKAY [ 0.010s]

Writing 'multiimgoem_b' OKAY [ 0.003s]

Finished. Total time: 0.027s

Sending 'uefisecapp_a' (2048 KB) OKAY [ 0.055s]

Writing 'uefisecapp_a' OKAY [ 0.008s]

Finished. Total time: 0.077s

Sending 'uefisecapp_b' (2048 KB) OKAY [ 0.065s]

Writing 'uefisecapp_b' OKAY [ 0.017s]

Finished. Total time: 0.097s

Sending 'recovery_a' (98304 KB) OKAY [ 2.509s]

Writing 'recovery_a' OKAY [ 0.392s]

Finished. Total time: 2.918s

Sending 'recovery_b' (98304 KB) OKAY [ 2.638s]

Writing 'recovery_b' OKAY [ 0.416s]

Finished. Total time: 3.068s

fastboot: error: Failed to find AVB_MAGIC at offset: 0

fastboot: error: Failed to find AVB_MAGIC at offset: 0

Sending 'vbmeta_system_a' (64 KB) OKAY [ 0.015s]

Writing 'vbmeta_system_a' OKAY [ 0.006s]

Finished. Total time: 0.044s

Sending 'vbmeta_system_b' (64 KB) OKAY [ 0.008s]

Writing 'vbmeta_system_b' OKAY [ 0.004s]

Finished. Total time: 0.032s

Rebooting before flashing super...

Rebooting into fastboot OKAY [ 0.003s]

< waiting for any device >

^C