I see this on many tanks. Silicone around the bottom is thick because it is never seen and doesn't have to look pretty. On the vertical edges, it only may feather out 1/4-3/8" onto both panes. This is fine.
My tanks: 120 Reef w/L2 Algae Scrubber, 60 Reef Pond w/floating Algae Scrubber, 40 Breeder Reef w/L2 UAS Tester Algae Scrubber
I maintain: 144 SW Reef w/L2 Algae Scrubber | 200 SW Reef w/L4 Algae Scrubber
Special knowledge: Algae Scrubbers, Acrylic Fabrication