Here is the most likely cause of your problem (see first image):
CPU maxed-out, and no free memory. The page file will be thrashing also.

In Task Manager, click on Processes tab (or details tab) and then click on the CPU column to sort by CPU, and see what tasks are using the processor (see second image). Do let us know the findings.

Attached Files (Click to download or enlarge) (Only available when you are logged in)
2020-05-08_18-55-41.jpg (249.75 KB, 105 downloads)
2020-05-08_18-59-59.jpg (223.19 KB, 105 downloads)

BIAB & RB2026 Win.(Audiophile), Windows 10 Pro & Windows 11, Cakewalk Bandlab, Izotope Prod.Bundle, Roland RD-1000, Synthogy Ivory, Session Keys Grand S & Electric R, Kontakt, Focusrite 18i20, KetronSD2, NS40M, Pioneer Active Monitors.