GRC blocks become unresponsive w data stored in Variable Blocks

Hello GNURadio Community,  

Several Gnuradio tutorials show Variable Blocks that compute filter coefficients which are passed as input parameters to dsp signal processing blocks. In the past, I designed a GRC flow graph with a Variable Block that computes filter coefficients that were passed as an input parameter to a C++ OOT block I made. In the GRC, it is easy for me to import the scipy library and use a Variable Block to access the scipy library and conveniently design a filter that that does not exist in Gnuradio C++ library and pass the coefficients as an input parameter to my C++ signal processing block. 

I recently built a C++ OOT block which requires long filter lengths and four sets of filter coefficients rather than one. Problems are: 

Problem 1. When I type gnuradio-companion in the terminal and hit enter, it takes forever to load the GRC flow graph. 

Problem 2. When the GRC Flow Graph opens, if I click on any of the blocks, it takes forever to open and the same goes for editing and closing the block. 

Is it a problem that the GRC flow graph becomes unresponsive when there are filter coefficients to compute in Variable Blocks?  Because if I disable these Variable Blocks, things become normal and responsive again.

I would appreciate any suggestions!

Regards,

George