Here is the difference in output using hardware serial and software serial, both on Pro Mini (ATMega328) 3.3V
Output using NewSoftSerial
$GPG,23m9t9.737,,,\,0,0,\,,,M,,*lB
$G G?A,A\1,,,\,,,,,\,L,,,7T$GPGA,b3u949.x36,,\,,0\0L,,M\,M,l*45
$G G?A,A\1,,\,,,\,L,,,\,lCN
$GPGA,b3u949^9s7,,,\,0,`,L,M,\M,,*l5
LG°GSA\AL1,,\,,,\,L,,,\,L*10$GPGA,b3u950^036L,,,\0,0\,LM,,,,*l5
LGGSA\A,1L,,,\,,,\,l,,,\6,$GPGA,b3u950^136L,,,\0L0,,\M,,,,*l4
LGGSA\AL1,,\,,,\,L,,,\,L*10$GPGA,b3u950^2s7,,,\,0,0,\,M,\M,,*l6
$G GSA\AL1,,\,L,,,\,,,\,l*0N$GPG,23i950^3s6,,\,l0,0\,,M\,,,*l6
$G G?A,A\1,,\,L,,,\,L,,,\*0,$GPGA,b3u950^4s7,,,\,0,0,\,M,\M,,*l0
LGGSA\Al1,,\,L,,,\,,,\,l*00$GPG,23m950^5s6,,\,L0,0\,,M\,,,*l0
$G GSA\Al1,,\,L,,,\,L,,,\*N$GPG,23m9u0.6g6,,\,l0,0\,lM,,,,*l3
$G G³A,A\1,,\,L,,,\,l,,,\*6,$GPG,23m950^7s7,,\,l0,0\,,M,\M,,*l3
$G GSA\A,1,,\,L,,,\,,,\,l5T$GPG,23m950^8s6,,,\,0,0,\,Í,,M,,*lD
$G G³A,A\1,,\,L,,,\,L,,,\*,.$GPG,23m950^9s7,,,\,0,0,\,M,,,,*dD
Output using hardware serial
$GPVTG,0.00,T,,M,0.00,N,0.00,K,N*32
$GPGGA,235946.837,,,,,0,0,,,M,,M,,*4B
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GPRMC,235946.837,V,,,,,0.00,0.00,050180,,,N*42
$GPVTG,0.00,T,,M,0.00,N,0.00,K,N*32
$GPGGA,235946.937,,,,,0,0,,,M,,M,,*4A
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GPRMC,235946.937,V,,,,,0.00,0.00,050180,,,N*43
$GPVTG,0.00,T,,M,0.00,N,0.00,K,N*32
$GPGGA,235947.036,,,,,0,0,,,M,,M,,*43
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GPRMC,235947.036,V,,,,,0.00,0.00,050180,,,N*4A
$GPVTG,0.00,T,,M,0.00,N,0.00,K,N*32
$GPGGA,235947.137,,,,,0,0,,,M,,M,,*43
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
I have also tried different Pins, but same issue.