Gigablast is intermittent and less than 100 mbs

My husband started working  from home in March. We have gigablast so theoretically he should be fine with an ethernet connection. However our ethernet and wifi speeds have been between 40 to 150. We've bought a new router, we've bought new ethernet cables and no improvement. We had a tech out here a few weeks ago, but they couldn't come into the house and said everything was fine outside. Now it's just intermittent internet period. I have another tech that still cannot come into my house coming on Monday but at this point I might as well switch to the 150 mbs level and save some money. Is there anything left to try?