Cracking in grout over spillway tiles from attached Spa

[drimran]

Hi everyone just looking for recommendation on any repair advice on cracks in grout located from attach spa spillway into a pool. Would appreciate any advice on materials to use to seal the cracks.
Had this happen previously two years ago and had tiles repaired I was hoping to get this fixed before tiles became loose and bigger issue.
Please see attached pictures.

 

[Rancho Cost-a-Lotta]

Did you find an answer yet? I found this using the search function:

best way to reinstall spillover spa

I have had to repair my spillover for my spa 3x in 10 years each time the mortar fails as water undermines the 5 stones each stone is indiana ledgerock about 3-4 inches thick with a crack of about 1/2 inch between the stones they are laid on a bed of mortar and then grouted together in the...

www.troublefreepool.com

I recently saw a recommendation by @ajw22, but I can't find it now.