Is your Rogers box connected directly to your TV?
Sometime there are issues if passing through other audio/video components.
I think the 1080p setting, may have been alot of your HDMI issue.. hopefully leaving it on 1080i should fix it.
(many people have had 1080p problems)
As for the rebooting.. most people it seems, over the first few days of having a box, have had 1 or so random reboots.. likely getting final updates to make sure its current, etc.. but have seemed pretty stable otherwise.
(even the NB2 had these ocassionaly).
If you were swapping boxes regularily, this may have cropped up again, as the next one you got, needed to do the same update, etc.
This is Rogers doing this on purpose. They do not want people using HDMI cables. What bothers me is they seem to have reset something on my actual television. Have been through a full day of testing. Used two televisions, two HDMI cables, the Nextbox and another box. Plus TV has two HDMI connectors. Suddenly stopped working on TV#1 today, rebooted Nextbox 8642, changed to HDMI2 plug on TV. Nothing worked. Disconnected 8642 on TV#1, connected other box to HDMI1 and HDMI2. Nothing worked. Therefore at this point I thought it is either my television or something Rogers did. Unplugged TV#1. Plugged in TV#2, connected HDMI2 directly from TV#1 without rebooting Nextbox 8642. It worked! Within about ten seconds TV#2 started to FLASH!! It worked, then white screen, it worked, then white screen. I quickly unplugged TV#2 from the HDMI. Plugged in TV#1 (it had been off for about half an hour at that point) and it worked again! Started watching a movie half way through FLASH "No signal". Went back and got TV#2. Plugged it in again and it did not work with the Nextbox 8642. So I plugged the other box in to TV#2 and it worked on HDMI. So at this point I tried Nextbox8642 again on both TV's. Will not work on either TV on HDMI. Again, plugged in "Other box" now not working on either TV. So now wondering if Rogers has done something to the HDMI on my personal equipment? Seen other posts that say it is the HDCP (which is a handshake). Therefore, Nextbox/Rogers not seeing/supporting HDMI but they won't tell you that. They don't want clients using movie boxes. These boxes connect via HDMI. So they are tampering with the HDMI or HDCP. Then nicely "suggest" using the other cables.
I find these tactics underhanded considering the money we pay for their services. HDMI service and now we can't watch HD! Why, because they block HDCP.
Just out of curiosity. Anyone else this is happening to own their Nextbox by chance. I did a rent to own plan a few years ago so own mine since 2015. Forcing people who own to update their Nextbox means $24.9? a month rental again for them too you know.
Now connected with coax, no HD, sound keeps cutting out. Rogers is doing something.
Not the first time I have been through this kind of thing either. Last time they tried to convince me my television was not compatible with their Nextbox/remote. However I had already been using them together for years. So, it was an update they did. Would not admit at all it was an update that did this. Imagine the guy was trying to convince me the only solution would be a new TV. That was until I went in to the next room got TV#2 tested it and it worked... Same brand model TV. That has saved my bacon twice now (having two TV's that are exactly the same) for testing. Good luck, we need it.
HDMI can sometimes cause issues if you have an older TV and Rogers brings out new firmware. New firmware recently "forced" a handshake on some TVs that caused problems because it then tried to send a 1080P signal to some TVs that couldn't handle it, or simply had older firmware. Make sure the firmware on your TVs is up-to-date.
You can try going into the Rogers box Settings - Appearance and select 1080i, instead of Auto. This may cure your issue. Also, a "white screen" often indicates either a handshake issue or a poor connection - cables can become loose in the ports or the ports can become oxidized. Even one small pin can cause problems.
Here's a post on the topic of changing from Auto to 1080i if you cannot go into the settings or if nothing shows on the screen with HDMI. Rogers recently brought out this option to allow you to choose a format when some people with older TVs were having problems.