@a7x88 sorry to hear your Roku streaming stick totally gave up its ghost on you... did you ever pick up a replacement of any variety? I have a similar situation, or difficulty with the Roku Remote App for Android not working with my television. I believe this to be due to the network setup which you also mentioned might be a factor in your instance, with multiple VLANs for network segmentation.
I have this TCL 55" CLASS P6-SERIES 4K UHD DOLBY VISION HDR ROKU SMART TV - 55P607, which came with this remote: Our Android phones, tablets, PCs, et cetera are on the primary/"main" device LAN subnet (10.0.0.0/24) and the Roku TV (as well as all other smart home/speakers, gaming consoles, Chromecast, IoT devices and so on) are segmented off onto their own "IoT" subnet (10.1.1.0/24) -- but i am unable to use the Roku Remote TV app to control my TCL set. I've got mDNS properly enabled, as I am now able to sling content to my Chromecast, which is behind the same, aforementioned VLAN segmentation -- now dabbling with IGMP on my Edgerouter, but to no avail (yet). Would be curious to hear any feedback or results you've encountered in your attempts along the way.