What you are seeing is probably AgCl, which is readily formed when you have Ag+ and Cl- ions in solution. Perhaps you could try using a different type of reference electrode that does not contain Cl- or isolate your reference with a luggin probe in a different electrolyte.

Daniel Torres Thank You Sir

you also precipitate AgCl within the diaphragm of the reference. thats bad.

use a double chamber reference and LiAc or KNO3 as outer electrolyte

As the answers above make clear, your reference electrode filling solution (probably NaCl or KCl) is diffusing out (or maybe pouring through, if the liquid level in the reference is above the level of your test solution) precipitating your Ag+ as AgCl. Reference electrode frits need to be permeable, so this is unavoidable as the experiment is set up. However, you might want to use a double junction reference with the intermediate solution as KNO3 or some other strong electrolyte that won''t cause your Ag+ to crash out. If you don't want to make your own, double junction (or so-called non-leak) reference electrodes are widely commercially available.

and the simple solution would be to use a blank siver wire directly in the AgNO3 electrolyte; forms a first order half cell.

as well a large silver counter in 2 electrodes mode does the job.

Dear Sachin Kumar ,

with the help of a (large - CE) Ag Counter Electrode, in a (2 electrodes configuration mode) simpler cell[1], similar to your cell[2], will do, even better[3], your job.

1. As Gerhard Jobst said, above, 4 days, ago.

2. Electrolysis of an aqueous solution of AgNO3​ with silver electrodes... https://www.toppr.com/ask/question/electrolysis-of-an-aqueous-solution-of-agno3-with-silver-electrodes/

3. Silver Electrodeposition from AgNO3 Solutions Containing Organic Additives: Electrodeposition from Binary Water–Methanol Solvent Systems in the Presence of Tartaric Acid https://link.springer.com/article/10.1023/B:JACH.0000021920.59845.4c

If the reference electrode has not been used for a while it is often a good idea to remake it, particularly if the chloride layer on the silver is no longer all dark brown (strip the AgCl from the Ag wire with ammonia and redeposit, replenish the KCl storage solution and also clean the frit by sonicating in DI water to prevent blockages) as this may affect the potential you are applying therefore the deposition process. Another point to consider is that Ag/AgCl as a reference electrode is best (and very stable) in an aqueous chloride solution so there are common ions, so depending on your system it may be perhaps not the reference electrode for the job.