@Dava I just did this a few days ago, I also had a hard time finding a ROM. I finally got one called "Lenovo_Tab_M10_FHD_Plus_TB-606F_MT6765_HW60_S100055_2001030016_V5.196_BMP_ROW.zip" that worked for me. I had to use spflash tool and cannot remember if I checked or unchecked the preloader, one worked for me while the other did not. I also had to use a tool called "mtk_bypass_rev3" to even be able to flash it with the spflashtool. I got the ROM from a site called "addrom.com" I cannot say anything about that site or it's safety but it worked for me. If I am allowed to post links here is the download page, just scroll down to find the one I was talking about: https://addrom.com/stock-rom-firmware-for-lenovo-tab-m10-hd-plus-tb-x606/