Although grassy weed ID can be challenging since it relies on nuanced details hard to see in photos, the growth habit of the pictured weed (plus the fact that it's still growing in this weather) suggests Bermudagrass.

It is hard to control, requiring either physical removal or spot-treatment with a systemic, non-selective herbicide like glyphosate to kill the root system. (This will damage or kill any fescue the spray touches, but to be fair, removal by digging will also take out some fescue with it.) The area can then be repaired with seed or sod once the weather cools (not now).

Miri

I have in some mulch beds near trees and shrubs.  Would the spot treatment be okay to use in those areas?

Yes, if the spray does not contact the desirable plants in the bed (this pertains to both foliage and bark). You can use a scrap piece of cardboard or a similar disposable barrier material to help prevent spray drift from wafting or dripping onto nearby foliage. Even though your goal with herbicide is to kill the weeds, heed any temperature restrictions on the product label; it might not be able to be applied while temperatures are above 85 degrees, though that might depend on the formulation. Fortunately, glyphosate doesn't tend to volatilize (become airborne or gaseous due to evaporation), but if other herbicide ingredients were being used, they could volatilize, and that would put nearby desirable plants at higher risk of damage.

Miri