Thank you Ayodele_Akande,
since you are asking about alternatives and planning to contact your dealer tomorrow, the least expensive solution would be this:
Are you somewhat tech savvy, or is there a friend or family member like that? I ask because the procedure of changing a RAM module is really not difficult.
All you have to do is unscrew the housing, fold up the old module, remove it and insert the newly purchased one. Costs between 20 and 30€ here in Germany.
Since a Nucleus is basically an Intel NUC in a different case, there are plenty of instructions and even videos available. Certainly help here by the community as well.
Here is a link to a thread I just recall where you can see what the inside of your Nucleus, and the same RAM sticks you will need, looks like.
If that is not an option, you will need to ask your dealer if he can make the exchange himself or if he can direct you to someone else.
(This case might be more appropriate for a computer savvy than a hifi dealer.)
If it was my own problem, I would consider the following:
It’s likely that after upgrading your Nucleus with a new RAM module, everything will work again for a while. However, it can happen that one or both SSDs fail later. Or another hardware element. Or that the overall processor performance no longer meets your requirements.
If your dealer is someone you can trust and who you can expect to give useful advice, I would discuss these aspects with him.