Not receiving Text Messages inside my house.

I have zero or one bar of cell signal inside my house due to the house’s location and elevation in relation to the nearest cell tower.  The weak signal is causing some Text Messages to not arrive on my phone when I’m in the house.  When I walk outside, then I receive several messages all at once.

The cell signal strength at the house has never been great, but seems to have gotten worse around the time I got a new Samsung S21 Ultra phone a month ago. Hard to say for sure that the new phone has poorer signal reception than the old phone.

XM Support had me do a "Reset Network Settings" which did not improve the situation.

Any suggestions?

Anyone have luck with one of the "Cell Phone Signal Booster" units sold on Amazon?