Do the accounts that you are leaving the reviews from match the geo of the GMB listing? Nowadays, that is by far the biggest predictor of whether or not the review will stick. If you've had a bunch of reviews removed from your listing in the past on the basis of being fake, your stickiness rate, even from legitimate accounts will suffer drastically in the future. Adding a bunch of fake reviews as a long-term ORM strategy is slowly beginning to die anyways, you're much better off simply incentivizing your legitimate customers to leave positive reviews through discounts or promotions and then removing any negative reviews through removal services/strategies. It's a far healthier alternative for your GMB than simply adding hundreds of inauthentic reviews like people were doing a year ago imo.