According to Acer your laptop has a one year Warranty on it unless it was purchased before 2019.
Anyways, it is possible when Acer repaired your laptop they may have loosened up or did something to GPU card on the motherboard.
Need to find out if Acer Warranty Repairs has a Warranty period on it if your original Warranty has expired.
See if your Acer laptop has its own Diagnostic Software to check your laptop's hardware and software. If it does run it and see what comes up if anything.
Found this at Acer about diagnostics: https://www.acer.com/ac/en/US/content/software-acer-care-center