That's a nice looking pleco. If it's anything like the Panaque maccus, clown pleco, you may not see it very often.
Please dont tell me that. I have a clown in another tank and I have seen it twice in 5 months.
A trick with the clown pleco would be to put driftwood near the front and angled so you can see under it. And ideally have that be the only piece of driftwood. Otherwise, as mentioned they do hide a lot.
I think you'll find the Royal especially a lot less shy, and the Blue panaque as well...but the same trick will likely work, to put a good hiding spot of driftwood in a nice visible spot.
The clown and royal are in another tank. The Royal is too big to hide. :-) I put a piece of driftwood in there, didnt have any before. And he has been on the wood constatly now.
Now, the Blue... there is a lot of driftwood in this tank... I am not sure I will ever see it.

The bristlenose in here is very active and comes out all the time... comes right up to the clip that I put cucumber on. Hopefully the Blue will learn about this clip also.