Is anyone taking Losartan for high blood pressure?

Anyone having kidney side effects from the blood pressure medicine Losartan? For about 3 years I was doing well on it keeping my BP within 120/60. Recently it’s started going up like 140/59, 143/72. My kidney test result from 2017 said my GFR was 40 mL/min. It is supposed to be >60.

Recently my brother who is also a diabetic went to his nephrologist and she immediately told him to get off the Losartan. His GFR was 44. He went off the Losartan for 4 days, had the test again and his GFR was 66! In four days it made that much difference?

Just curious if anyone else has had results like this going off of it? Because my BP is rising I’m wondering if I need to switch to a different BP medication. I understand that Avapro, and Atacand which are also AT1 receptors in some studies showed to
work better that Lasartan.