Could not figure out the exact reason why page view and button is changing to Link and page color is changing when bsp page url uses a public IP

Hello Expert,

My requiremet :  I have to call a bill desk(for online payment like VISA/Msstercard) url from one bsp page .BSP page URL should be (in Public IP) from which bill desk gateway will be called. I call my bsp page from  webdynpro button event in srm portal.

For example :  Lets say my BSP page url is as below and when I click  “My Payment” button Some bill desk url will be called:

http://abc11.sdc.def:8000/sap/bc/bsp/sap/ztenderpayment/zpaymentreq.htm

and above link is actually called with parameter as below :

http://abc11.sdc.def:8000/sap/bc/bsp/sap/ztenderpayment/zpaymentreq.htm?VNO=0001000050&VID=AT&T=&TNO=0000003845&TDESC=SDEMC001%2029%2e01%2e2016%2011%3a28&PGV=TPSL&CRN=INR&PTYPE=EMD&AMT=0%2e00

When I use public IP as http://stv.erp.vvv:8080/zpaymentdev then correct data came but the BSP page color is changing and button like “Make Payment” is showing like a link as below:

  http://stv.erp.vvvv:8080/sap(bD1lbiZjPTEwMA==)/bc/bsp/sap/ztenderpayment/zpaymentreq.htm?VNO=0001000050&VID=AT&T=&TNO=0000003845&TDESC=SDEMC001%2029%2e01%2e2016%2011%3a28&PGV=TPSL&CRN=INR&PTYPE=EMD&AMT=0%2e00

I could not figure out the exact reason why button is changing to Link and page color is changing while rendering html.

Can anybody help with proper solution, I tried with pure html elements instead of htmlb elements but same result came. Is there any configuration or role or profile need to be changed? Or any other solution.

Thanks & Regards,

Partha