Maybe it will be clear to someone else, but I have no idea what you mean when you say your "pool has been bubbling". I assume that you mean bubbles are coming out somewhere, but that's all I can figure. How coping, or a pool shelf, could make a pool bubble is more than I can guess.
. . . if you mean that water appears underneath your liner, as trapped 'bubbles', then that's something else.
Simple hydraulic principles govern that: if the water level in the ground around the pool is higher than the water level in the pool . . . you'll tend get water 'bubbles' behind the liner, regardless of pool shelves, coping, or any other such thing. If they water level in the ground is NOT higher than the water level in the pool . . . you will NOT get water 'bubbles' under the liner.
I suppose it's possible to get runoff, or gutter drainage, entering the ground -- behind the coping, maybe? -- so that the ground water level just around your pool is higher than the ground water level generally.
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