acrylic seal sealed sealant

Hello, I have a 180g acrylic tank on a solid wood stand and solid wood canopy. I’ve noticed what almost looks like inner seams of the acrylic perhaps seperating? Could someone please let me know what is happening and if it’s safe? If not, any next steps. All help is appreciated. Thank you.

Does aquarium sealant bond onto Acrylic? Thanks in advance guys for your input.