I am the same, had not seen my M. Balfouri for about 3 months so just had to dig it out and make sure all ok. It was, it was soooo pissed with me tho.....lol. I reckon due a molt too looking at size of abdomen so I feel a real idiot. We always advise not to do it, then we break our own rules. My badThey will become more visible as they get older... don't worry. As youngsters, they burrow all the time. Mine has completely buried herself and digs a nice tunnel to the surface when she wants me to fill her belly. She is also about 3".
My tiny 1/4" spiderling is nowhere to be seen. I worry about them, but I don't want to constantly dig them out either.