The house I bought came with a large natural flagstone patio which is covered. The flagstone is mortared together. The mortar is cracking in multiple places and part of the patio is now sloping. Half of the flagstone patio which is laid against a concrete walkway which goes around the house is in good condition and is still level with no cracking. On further inspection of the sloping cracked area it seems like the stones were laid on a gravel type of base and then mortared together. The diagram below outlines what the patio looks like. The entire flagstone patio (300+ square feet) plus a large dirt patch (300 square feet) is completely covered. There is a small, bricked retaining wall on the left of the diagram which separates the grass yard from the flagstone patio. Our plan is to eventually install artificial turf where the dirt patch is located, fix the flagstone patio, and make the walkway wider (as it has started to crack and washout).

With all the research I have done it seems like dry laying flagstone and using mortar is not an ideal method. Is it possible to fix the existing flagstone and level it without ripping the entire patio out and starting over?? The blue areas in the diagram are the places the patio has started to slope with cracked mortar. I will also attach some pictures of the patio (which are not the best quality unfortunately).

area on the left of the diagram where sloping and cracking is occurring

walkway with cracked and washed-out mortar