I upgraded LNB8105X to DH_IPC-HX2X3X-Rhea_MultiLang_NP_Stream2_V2.800.0000016.0.R.200605.bin via TFTP, and then was able to upgrade via GUI to DH_IPC-HX2X3X-Rhea_MultiLang_NP_Stream2_V2.800.0000018.0.R.210707.bin. I did it recently, so not sure how reliable it will be. After upgrade IVS became available, which seems to work fine so far.
This is the first report I've seen of a successful tftp upgrade of the Lorex version of this camera.
How did you perform this upgrade? Standard TFTP update?
I had one camera that came with my Lorex setup that was mistakenly running Dahua out of the box, but could not get the others that were running Lorex firmware to take the Dahua firmware via TFTP.