Leopard Wrasse and purple dottyback hiding

Hi all, on Tuesday I added a female leopard wrasse and a purple dottyback to my 75 gallon reef. The system is 3 years old with coral and is well established with pods. Currently I have 2 clowns, a sleeper banded goby, yellow tang, 2 green madarins, a lawnmower blenny, and an Anthias. There is no conflict in the tank... I spent a lot of time watching the behavior both from being in proximity (10 feet away from) and from the live video feed I have of my system. On tuesday, I drip acclimated both fish and added them. The wrasse hid the rest of the day in the sand, half buried which I expected, and the dottyback darted in and out of the rock work. The wrasse was out swimming freely the following morning under the actinics as was the dottyback, both completely unharrassed. When the rest of my lights clicked on, the wrasse immediately buried himself in the sand, and the dottyback still was in and out of the rockwork. I have not seen the wrasse since... how long can they stay buried? I had a 6 line 2 years ago do the same thing and never reappear, with no evidence of jumping. Now, on Wednesday night, I saw the dottyback for the last time. How long can they stay hidden? I'm not at home today to check parameters, but I do keep a close eye on them and have had no trouble for months. I know pulling apart rockwork is a bad idea, but given my amount and placement of coral it's not even an option anyways. I'm just looking for reassurance that they might still be alive... any help or advice is appreciated.