Do road tubeless tyres lose air faster? I just replaced my rear wheel with a road tubeless (Bontrager RL TLR). Was lucky to have the bike shop installed the tyre, took two blokes to put it on the rim. Anyway, my second ride was a couple of days after I bought it and I can feel the wheel bumped a gap on the driveway. So I went back and put some more air to 90 psi.

Two days after I pumped the tyre, I checked the tyre before riding and it only had 40 psi. Is that normal for road tubeless? I only have to add air once a week with none tubeless tyre.

Follow up

I went back to the shop and they said they put enough sealant and insisted that rapid air loss is normal for tubeless. They also offered to put tube in it if it's too much a pain. Caveat, I asked how others' experience with road tubeless and they said I'm the only one with tubeless. I did see there's a stack of TLR rim strip, presumably from new Trek bikes they sold that came with Bontrager TLR wheels.

I sent a link to this question to them and trek, no response yet.

For now, I will just pump the tyres before every ride.

Edit

To clarify, my question is only about road tubeless tyres relative to road clincher, so they're both "high pressure" tyres. I actually ran the tubeless with less air (90 psi) compared to my front clincher tyre (100 psi). The reason for that was because the tubeless rim is a "wide rim" than (then) usual road wheels.

In case anyone's interested, I only have tubeless wheels now and run them with tubes because 1) losing air was too much trouble and 2) I don't think I can put on a tubeless tyre myself.
You're really asking two questions here:
1) Do road tires lose air more quickly?
And 2) Do tubeless tires lose air more quickly?

First off, let's talk about the different ways that tires can (and do) lose pressure. 

Obviously, they can lose pressure through a poor seal, either on the valve or where the tire seats to the rim on tubeless tires. 

Tires also lose pressure through permeation. This essentially means that air molecules escape between the molecules that make up the casing (i.e., tube or tubeless tire). This is true of all tires, not just bicycle tires.

And of course, there is always the possibility of a slow leak caused by a puncture.

No matter what the reason for air loss, a tire at a higher pressure will lose air more quickly than a tire at a lower pressure. Thus, if we assume the same type of tire, materials, etc: road tires lose air more quickly than cross tires, and cross tires lose air more quickly than mountain bike tires. 

Additionally, air loss is also more noticeable on smaller tires because any air that escapes represents a larger percentage of the total volume of air. So, if you have a 26x2 mountain bike tire and a 700x23c and inflate them both to the same pressure, they will initially lose the same amount of air at the same rate. However, since the air lost in the road tire represents a larger percentage of the overall volume, the pressure will drop more quickly. And as the pressure drops, the road tire will lose air more slowly, but the pressure will still drop more quickly than the mountain bike tire due to its significantly greater size.   

Air loss is also exacerbated by thinner walled casings. This means that (again, assuming the same materials) lighter and thinner tubes will lose air more quickly than heavier and thicker tubes. 

Now, I don't have a lot of experience with tubeless, but given that caveat...

Tubeless tires should in theory lose air less quickly than tubes due to the thickness of the casing and the fact that people typically run them at lower pressures. I have heavily stressed "in theory" here because it is certainly possible that tubeless tires are more permeable than tubes and because of this, some balance is achieved.