Chat gpt 4o problem with file uploading and analysing

I upgraded again my chatgpt to chatgpt 4 and 4o but it look much worse than before. I have tried to upload a csv file and a text file and it said: Unable to extract text from “file”. And the reasoning too, I find it much weaker than the 3.5 version. So basically it didn’t help me at all today. I want to know if there is maybe a general problem or if others are experiencing the same as me, or is just like this. Because if so I return to chatgpt 3.5 which is also free. Appreciate any info. Thanks