Grout recommendations for porceline tile?

Here are some options:

https://www.familyhandyman.com/tiling/grouting/how-to-repair-grout-that-s-cracking/view-all/

http://homeguides.sfgate.com/regrout-top-grout-34870.html

Make sure you used the proper grout for the project. Unsanded grout should be used in joints that are less than 1/8-inch-wide. It has a smooth texture and clings well to vertical surfaces, which makes it useful for grouting ceramic wall tiles. Sanded grout should be used for flooring and wall tile joints wider than 1/8 inch because it resists shrinkage and cracking. I hope this helps. Good luck.

Grout is not a reason to replace tile. In fact, regular maintenance requires regrouting periodically. It works best if you use a grout remover tool first and remove all the grout. Then choose a grout that is suitable for porcelain (read the package). Grout removers are readily available in the tile section and are less than $10.