Bora Kaan Yılmaz Sorry, but you have not provided enough information to answer your question. These two individuals - are they from the same species, genotype, population, clonal group, and from the same round of DNA extraction? Your "different band patterns" - how are they different? Do they have a single band difference or all band were unique? Do you have a control genotype with known SSR profile? Do you know the expected SSR profile for your samples?
There could be several reasons for observing different band patterns in PCR despite using the same pair of primers. One possibility is that there was a mutation or variation in the target DNA sequence, leading to differences in amplification efficiency. Additionally, variations in the PCR conditions such as temperature, annealing time, or primer concentration could also contribute to the observed differences in band patterns.