Basilisk in general are among the things that are annoying to tame.

You need to make sure that they DON'T BURROW back. It means you have to make it keep chasing you or make it attack a pillar or a structure which makes glacial basilisk much easier to tame compared to the infernal basilisk.
When they burrow, they lose taming effectiveness, and its affinity starts going down till it reaches 0 and you have to restart taming again.

One of the tricks I know to stop it from burrowing is to let it bite you once in a while to keep the aggro on you. Luckily, its projectiles are easy to dodge but still dangerous due to AoE, pack your best armor, and a ton of Potions.

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tl;dr : keep running around the egg, heal if you get hit, don't let it burrow.

tried all of that. i went god mode cus it kept killing me. and every time it ate an egg, the taming meter reset. it also does this with a couple of other shadlos mods