Like all the above and to be honest I use to buy replacement cables on on the cheap as replacements when carrying out repairs (the customer new, however it was a cheap option than an original) however every single one without exception would come back no matter where I bought the cables from, you can't beat the original.
However it could be an expiation that you've gotten a faulty ssd the chances a slim but theres always a possibility. if you can next time you get the folder see if you can boot into network recovery and see the drive in Disk Utility, try running a first aid on it and see if you get any sort of errors.
Also as you haven't stated the year, the older versions of these MacBook Pros I believe used SATA II (3.0 Gb/s) this is rare but sometimes you can have problems with SATA III (6.0 Gb/s) SSD with a SATA II connection.
You say you changed the drive to an SSD, if the old HDD wasn't faulty and you still have it you can try that in a see if you still have the issues.