You could use some silicone sealant to hold them in place or a piece of rubber strip underneath.
Cap support
I replaced the cheap ASC axial caps in my DAC with AudioCaps. Even though they’re the same value, the AudioCaps are twice as large. In order to fit them in, the caps are standing much further off the circuit board. Is there any kind of material that can be used to support the weight of the caps from sagging while the unit is on? Or is not necessary? Thx.