This anomaly happens for goals which start immediately in the next 1-3 years and span for multiple years i.e at least 10-15 years. E.g. if today's date is 1st Jan 2018 the goal period could be say 2020-2039.
Let's further assume that the per year goal value is Rs.1,00,000. As such, the total present value will be Rs.20,00,000 (for 20 years).
In the above case, the goal value (also the Future Value) may be Rs.12,00,000 (actual value may vary depending on the inflation, asset allocation and equity/debt return assumed). Now, this value is the one that system calculates as on the first goal year - 2020 in the above case.
What it essentially means is that Rs.12,00,000 if accumulated in 2020 will take care of all the future year requirement up to 2039 such that the value in the year 2039 becomes 0. Important to note that Rs.12,00,000 is reinvested at a higher rate compared to the goal inflation. So, since only a small portion is required in the first goal year, the rest amount is reinvested at a higher rate (as decided by the goal's asset allocation) which is then used in the subsequent years resulting in this anomaly.
Workaround
A workaround is to break down the multi year goals into smaller buckets. Let's say, the first could be for the first 3-5 years and then create a second bucket for the rest of the years.