You have joined as a fresher candidate by SSC in another school with Hons./PG. It is proved that your MA degree is valid.
Now the question is continuation of service. Your Service will continue if you have applied through proper channel.
I have a few quarry-
a) Have you asked to submit at the time of personality test-(i) no objection certificate from previous school, (ii) certificate of teaching experience,(iii) xerox copy of service book and (iv) last pay certificate.
b) Have you submitted at the time of joining- (i) release order containing MC resolution ,(ii) service book from previous school (should be countersigned by the D.I. in case of district change),(iii) L.P.C.,(iv) statement of P.F./transfer of P.F.
If the all answer are yes, then it will be treated as continuous service ,otherwise not.
Thank you.