The previous owner used tile not intended for a shower. So it’s not good…. Need to either replace it or seal it 

 Oyyy I’d probably replace it. I’d worry any sealer applied afterwards would degrade with cleaning. 

 Unfortunately that would be a complete bathroom Reno which I’m not wanting to do lol. Sigh 

 Understandable. Where’s the fairy godmother and her magic wand when you need her? 

 @NikkiNeighbor has some ideas I’m sure haha