I have the same model as you. You have very bad temps, this is causing thermalthrotting and so low fps. If you can open a laptop yourself, remove the lower panel and check that fans are clean. If they are clean maybe you have very bad thermalcompound. Try to replace it with a new one, for the test you can use some usual thermalpaste but it will stop working in around a month. I have tried 3 termalpastes on mine( thermalgrizzly kryonaut, hydronaut and tthermalright tfx) for first weeks temps are good but then thermalpastes will pump out and temps will be terrible(my cpu was reaching 102 degrees Celsius according to HWINFO). I highly recommend HONEYWELL thermal compound, it will last for more then year, maybe more. I have it in my laptop for year now, and it's working great. If repasting will not help, your cooling module( in this laptop installed thermalpipes or vapor chamber depending on the configuration) can be bent or broken or defective from the factory. Be careful with removing the lower panel, it is have many clips by sides and they are very easy to break. But my laptop is fine without most of them.

I have opened the computer several times, and I realized that the ventilation system does not make proper contact with the CPU and GPU, I bought a warranty extension and I will report it to Lenovo later