To update all. Had a engineer call 6/10. Found V6 box to be slow to requests and did see how the picture kept stalling/cutting out (not sure what to call it) like it couldn't spool quicker enough.
Anyway they have replaced the V6 box with a new one and intially seems to be quicker to my requests. Will now see how "catch up" and "on demand" do over the next week and if continues will advise.
The engineer also found from the intial installation back in 2016 I think they'd put a sort surge protector between the box and cable, it's similar to what I have on my TV aerial incase of lightening or something. Anyway he said this was reducing the signal strength as well. So possibly two issues slow box and this thing.
First time catch-up & on-demand used worked seemlessly and was fast, I made sure I used each option. However still fine no blips or pausing when requesting either catch-up or on-demand but has slowed fractionally in when you fast forward the picture now stays static so you have to watch the timer (i don't like ads etc.).
In terms of sudden reboots currently experienced none but will advise if it starts to happen. I would finish off and say the box itself is reacting to my requests quicker in terms of channel changing, pause/stop etc. and delete. So currently a happy customer waiting on free upgrade to TiVo box where you can record 6 channels.
Thank you for coming back to us and updating the thread about how your appointment went. We're glad to hear that your replaced TV box is working and you're not experiencing any issues that you had before.
Please keep us update on this and let us know if you need any further help or assistance with this.
Spoke a little too soon, 20/10 and 21/10 sudden reboot boot happened, this occurred when I'd finih watching a recorded programme and went to the delete option.
Also on catch up watched a couple of programmes and one was fine, the other showed some stuttering/spooling but only once and minor. I will try and get into the habit of recording time/date etc. for reference.