Same model, but the interface showed build 20180316 as "up to date", and when I've tried manually downloading the 2019 build it showed "invalid type". Swapped i

Same model, but the interface showed build 20180316 as "up to date", and when I've tried manually downloading the 2019 build it showed "invalid type". Swapped it with DD-wrt not long ago (DD-wrt support was why I've decided on this model, but I was too lazy to do that before).