Using Serial and one softwareserial works perfectly well so far.
Use AltSoftSerial instead of SoftwareSerial. But you have to use pins 8 & 9. If you can't use those two pins, try NeoSWSerial instead of SoftwareSerial.
I only run into troubles when I use 2 softwareSerials at the same time.
How many times does it take? YOU CAN'T DO THAT.
With your AltSoftSerial I'd also read from Serial and write on SoftwareSerial?
It's not mine.
You would read from Serial and write to AltSoftSerial. You could also read from AltSoftSerial and write to Serial, even at the same time. This is the BEST choice.
You could try Serial and NeoSWSerial (mine). This is the 2nd best choice.
Serial and SoftwareSerial might work, but SoftwareSerial cannot transmit and receive at the same time. Transmitting a character with SoftwareSerial prevents receiving a character on SoftwareSerial, and vice versa. At 9600, SoftwareSerial stops your Arduino from doing anything else, for 1ms at a time, when it sends or receives 1 character. This is the worst choice.