First, in principle, there should be no problem in resealing silica gel.
If we do not destroy the tile, it seems that there is no other good way except to glue and seal.
Second, I think the reason why the shower base often seeps water should be related to the way you glue.
1, First of all, the original sealant should be scraped before the sealant will clean up the gap, pay attention to be sure to let it fully dry before the next step;
2, sealant embedding depth should be greater than 3.5mm, but should not be greater than 4.5mm, too thin to ensure the quality of sealing, too thick is easy to be cold and thermal expansion and contraction and crack;
3, when buying sealant, we must pay attention to its guarantee period, and pay attention to the use of silicon structural adhesive, but should use silicon weatherproof sealant;
4, sealant filled, should be carefully checked sealant joints, such as bubbles, hollow, broken joints, inclusions and other defects, should be dealt with in time.
To keep the seam full, dense, continuous, uniform, no bubbles.
If you can pay attention to the above requirements when you inject glue next time, I think there should be no problem, because for your current situation, the use of silicone seal is yes, professional is also a feasible choice.
Wish you an early solution to the problem!