100% the show is suffering because of when it is.
I have to get up every morning at 5:30am and Blades ends at 1am. So right off the bat it's hard for me to justify staying up for the show. There's also the fact that by 9pm when the show starts, I've already been up for 16 hours, so I'm starting the show tried. Last night is a great example, where there was no CoS so I thought I'd stay up for Blades. I woke up this morning, stiff necked, face on my desk, not even remembering all of the Preshow, let alone anything that actually happened in the show...so now I'm going to have to watch the whole thing again.
If I'm struggling that hard to watch the show while living in NA, I can just imagine how impossible the time is for EU viewers. That's why I really only watch Blades Vod's. I think the sunday slow will help immensely.
Also worth remembering is that the show hasn't been super consistent the last few weeks, so it's entirely possible that inconsistency in shows also played a part in lower viewership. A ridiculous amount of people, after all these years, still haven't learned to follow Rollplay on Twitter, or just check your schedule page. Hell, I see people who are regulars on the channel coming into your Rollplay shows and asking how much they've missed (despite the shows always starting at the same time)! So schedule irregularities absolutely are going to mess with the show.
As far as the content itself, I think it's a show that deserves success. You have a great cast, great GM, interesting world and story, easy to understand mechanics, and great roleplaying. The show might be a little too serious for some people, but given how silly Nebula Jazz is, I think it's a nice contrast.
So I definitely hope you give the show a shot at a new timeslot before you consider giving it the axe.
edit: Oh, and keep in mind that Horizon Zero Dawn released yesterday, and that game had a fair bit of hype around it, so you may have also lost viewers to that.